Firefox 3 crashes during specific keyword searches

When I use either Yahoo search or Google to search for a specific website with Firefox 3, the browser shuts itself down entirely. Sometimes this is accompanied by a blank grey "pop-up" box which has to be exited multiple times to get rid of it, but this happens maybe once for every five times FF crashes. It has done this with several sites, but most recently with the keywords "sologig" and "simplysup". It does not actually access these sites; putting in the word and hitting "search" will cause it to shut down. Entering the full site in the browser address bar also causes FF to crash.

(It is not just these two sites; I have had the same problem searching for other known legitimate sites. It seems to be very random.)