070723 22:06:10InnoDB: Assertion failure in thread 1153587552 in file ./../include/buf0buf.ic line 626
InnoDB: Failing assertion: block->buf_fix_count > 0
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.0/en/forcing-recovery.html
InnoDB: about forcing recovery.
InnoDB: Thread 1161697632 stopped in file ./../include/sync0sync.ic line 111
InnoDB: Thread 1154128224 stopped in file ./../include/sync0sync.ic line 111
InnoDB: Thread 1148586336 stopped in file ./../include/sync0sync.ic line 111
InnoDB: Thread 1153046880 stopped in file ./../include/sync0sync.ic line 111
InnoDB: Thread 1098918240 stopped in file os0sync.c line 546
070723 22:06:10 - mysqld got signal 11;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help diagnose
the problem, but since we have already crashed, something is definitely wrong
and this may fail.

key_buffer_size=1258291200
read_buffer_size=4190208
max_used_connections=261
max_connections=500
threads_connected=7
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections = 5322796 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd=0x2aaaf9cd3fb0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
Cannot determine thread, fp=0x44c25068, backtrace may not be correct.
Stack range sanity check OK, backtrace follows:
(nil)
Stack trace seems successful - bottom reached
Please read http://dev.mysql.com/doc/mysql/en/using-stack-trace.html and follow instructions on how to resolve the stack trace. Resolved
stack trace is much more helpful in diagnosing the problem, so please do 
resolve it
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0x55555a50ee10 = SELECT p.post_id
	FROM community_posts p
	WHERE p.topic_id = 74505
		AND p.post_approved = 1
		
		
	ORDER BY p.post_time ASC
 LIMIT 15
thd->thread_id=992704
The manual page at http://www.mysql.com/doc/en/Crashing.html contains
information that should help you find out what is causing the crash.