The 522.11 webkit that safari 3 beta installed, appears to cause microsoft messenger to frequently crash.
Created attachment 14984 [details] Crash log from microsoft messenger.
Also, see this link. http://groups.google.com/group/microsoft.public.mac.messenger/browse_thread/thread/f3a95134aa1b9fba/f70721d1022a68bb
<rdar://problem/5269391>
The crash log attached here shows this was the same as <rdar://problem/5276135>, fixed in r23574.