A backtrace is available:

Array
(
    [0] => Array
        (
            [file] => C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\eventum\include\class.notification.php
            [line] => 620
            [function] => getFullName
            [class] => User
            [type] => ::
            [args] => Array
                (
                    [0] => Array
                        (
                        )

                )

        )

    [1] => Array
        (
            [file] => C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\eventum\include\class.issue.php
            [line] => 1500
            [function] => notifyIssueUpdated
            [class] => Notification
            [type] => ::
            [args] => Array
                (
                    [0] => 28
                    [1] => Array
                        (
                            [iss_id] => 28
                            [iss_customer_id] =>
                            [iss_customer_contact_id] =>
                            [iss_usr_id] => 10
                            [iss_grp_id] => 2
                            [iss_prj_id] => 2
                            [iss_prc_id] => 7
                            [iss_pre_id] => 0
                            [iss_pri_id] => 6
                            [iss_sta_id] => 10
                            [iss_res_id] => 1
                            [iss_duplicated_iss_id] =>
                            [iss_created_date] => Tue, 03 Apr 2007, 09:39:04 UTC
                            [iss_updated_date] => Tue, 03 Apr 2007, 09:56:39 UTC
                            [iss_last_response_date] =>
                            [iss_first_response_date] =>
                            [iss_closed_date] => 2007-04-03 09:56:38
                            [iss_last_customer_action_date] =>
                            [iss_expected_resolution_date] =>
                            [iss_summary] => Nike SA is off line
                            [iss_description] => It seems it was a network dip that caused Nike to go off line.
                            [iss_dev_time] => 0.5
                            [iss_developer_est_time] =>
                            [iss_impact_analysis] =>
                            [iss_contact_person_lname] =>
                            [iss_contact_person_fname] =>
                            [iss_contact_email] =>
                            [iss_contact_phone] =>
                            [iss_contact_timezone] =>
                            [iss_trigger_reminders] => 1
                            [iss_last_public_action_date] => 2007-04-03 09:56:38
                            [iss_last_public_action_type] => closed
                            [iss_last_internal_action_date] => 2007-04-03 09:56:39
                            [iss_last_internal_action_type] => time added
                            [iss_private] => 0
                            [iss_percent_complete] => 0
                            [iss_root_message_id] => <eventum.460lm1yq7.z4bbx9@10.200.64.234:90>
                            [prj_title] => Misccip
                            [prc_title] => Technical Assistance
                            [pre_title] =>
                            [pri_title] => P1 - System Down/Critical
                            [sta_title] => Close Call
                            [sta_abbreviation] => CLC
                            [status_color] => #FFFFFF
                            [sta_is_closed] => 1
                            [iss_original_description] => It seems it was a network dip that caused Nike to go off line.
                            [iss_created_date_ts] => 1175582344
                            [assignments] => Gustaaf von Pickartz
                            [authorized_repliers] => Array
                                (
                                    [users] => Array
                                        (
                                        )

                                    [other] => Array
                                        (
                                        )

                                    [all] => Array
                                        (
                                        )

                                )

                            [authorized_names] => Array
                                (
                                )

                            [has_inactive_users] => 0
                            [assigned_users] => Array
                                (
                                    [0] => 7
                                )

                            [assigned_inactive_users] => Array
                                (
                                )

                            [is_current_user_assigned] => 0
                            [associated_issues_details] => Array
                                (
                                )

                            [associated_issues] => Array
                                (
                                )

                            [reporter] => Neil Mclaren
                            [estimated_formatted_time] => 00m
                            [duplicates] =>
                            [duplicates_details] => Array
                                (
                                )

                            [group] => Array
                                (
                                    [grp_name] => EDI
                                    [grp_description] => EDI TEAM
                                    [grp_manager_usr_id] => 6
                                    [users] => Array
                                        (
                                            [0] => 6
                                            [1] => 7
                                            [2] => 8
                                        )

                                    [projects] => Array
                                        (
                                            [2] => Misccip
                                            [3] => Clockworks
                                            [4] => Micor Reporting
                                            [5] => AISI
                                        )

                                    [project_ids] => Array
                                        (
                                            [0] => 2
                                            [1] => 3
                                            [2] => 4
                                            [3] => 5
                                        )

                                    [manager] => Jaco van Dyk
                                )

                            [quarantine] =>
                        )

                    [2] => Array
                        (
                            [cat] => update
                            [issue_id] => 28
                            [resolution] => 1
                            [category] => 7
                            [status] => 10
                            [priority] => 8
                            [expected_resolution_date] =>
                            [percent_complete] => 0
                            [estimated_dev_time] => 0.5
                            [keep_assignments] => no
                            [search] => paste or start typing here
                            [group] => 6
                            [release] => 0
                            [summary] => Nike SA is off line
                            [description] => It seems it was a network dip that caused Nike to go off line.
                            [private] => 0
                            [trigger_reminders] => 1
                        )

                )

        )

    [2] => Array
        (
            [file] => C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\eventum\update.php
            [line] => 84
            [function] => update
            [class] => Issue
            [type] => ::
            [args] => Array
                (
                    [0] => 28
                )

        )

)