Description:
With a cluster up and running and a mysqld attached I shutdown and restarted the cluster.
I can not get the mysqld to attach and work on NDB related databases and tables until I
restart the mysqld process.

It will give the following message:
The error message inside the mysql client was:
mysql> create table t1 (c1 int, PRIMARY KEY(c1))ENGINE=NDB;
ERROR 1005 (HY000): Can't create table './test/t1.frm' (errno: 4009)

Not bad, but being a good MySQLer I wanted to know what a 4009 was:

./perror --ndb 4009
OS error code 4009:  Cluster Failure: Unknown result: Unknown result error

How to repeat:
Setup a cluster with a mysqld process attached. Shutdown and restart the cluster. Try to
do some work through a mysql client attached to the mysqd process.

Suggested fix:
reconnect to the cluster

issue arises when ndb_mgmd is restarted

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/26013

was pushed on the 15:th of june into 5.0,5.1

fixed in 5.0.8

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

Additional info:

Documented fix in MySQL Cluster 5.0.8 change history; marked bug as Closed.