After two years of excellent stability with Leopard on my 24" iMac, I moved to Snow Leopard and lost the ability to see networked PCs and started experiencing the type of multiple daily application crashes reported in this thread. After doing a lot of searching it appears that the problems may be related to poor implementation of network file sharing in 10.6. This may explain why some see excellent stability and others who have networked Macs are seeing crashes.
I found a blog on iLounge that may be useful at
http://www.ilounge.com/index.php/backstage/comments/two-proposed-solutions-to-sn ow-leopard-crash-problems-on-macs/. After following Solution B this morning, I have not had any application crashes all day - a new record since going to 10.6. Unfortunately, my Mac still cannot see any of my networked PCs or my NAS drive so I still have to decide whether it is worth the trouble and time it will take to go back to Leopard.
Interesting to hear whether others having problems with Snow Leopard have File Sharing turned on and if those reporting no problems do not.
By the way, when I went to Snow Leopard, I did a complete clean install instead of an upgrade and tried all the standard fixes, Safe Boot, Repair Disk Permissions, Repair Disk, Repair Permissions and nothing helped until now.
If what the folks at iLounge turn out to be correct, Apple should be ashamed of themselves for screwing up file sharing, which worked so well in Leopard, so badly.
Joel