vBulletin search is truly borked; always has been for this version.
Not sure if it's something that can get fixed or not; Scott would possibly know, but it ain't a good time to bug him, as you noted.
Sometimes a good search engine will search TIMO posts much better than the vBulletin engine does. If you really need to find stuff, try a TIMO specific search in google, like
this.
Cheers
Mick