It has to do with the search table, and, that is actually quite important to keeping VB healthy.....
On my forum I enabled searches down to two characters. Well, if you think about it, then the search engine has to go through and rank and store EVERY two character sequence on the site. It makes the search table millions of cells in size. And, it can more easily be corrupted.
The fix is to cut the searching off at three or even four characters. Make a difference in the search database size and reduces the chances of issues.
R