I was having an issue with Bridge CS3 in Mac OSX Snow Leopard - it was using half the CPU (i.e. 100% of one core) but didn’t appear to be doing much else - before eventually crashing. Having browsed around a bit last night and this morning to little avail, I thought I’d share the solution I eventually stumbled upon - to delete the cache. The official link is here, which includes information for both Windows and OSX users.

Thanks also to Planet Neil for the tip-off.