Search feature crash (can reproduce at will)

This is still a problem, it seems that most words I use to search causes this fatal error issue.

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 71 bytes) in /home/eforum/public_html/search.php on line 1155

The line number is always between 1152 and 1160

examples:
"call macro" FAIL
"macro" FAIL
"excel 2000 toolbar" FAIL
Its a crap shoot whether it works or fails.
I bet I have generated 20+ of these fatal errors from searching in the last two days.
I do not get this on other sites using vBullitin.