I recently upgraded to the T680 from a trusty old T600, and have not been happy thus far, due to endless random crashes. I think I've narrowed it down to the ROM apps I was hiding using Obfuscate.
I blithely went and hid anything I didn't expressly want to see in the Launcher, and this seems to have been the cause of all my crashes.

For example:
When receiving an incoming call, if I answered using the green button, I would get a dialog that said "Launch Error - The application can not be launched because of a system error." When I clicked ok to dismiss dialog, the phone would crash.

I realized that maybe by hiding certain apps from showing up in my Home screen, that I had also hidden them from the OS, so when it went looking to launch something, couldn't find it, and crashed.
So I told Obfuscate to show Applications, Phone, and some other obvious ones. [I haven't done enough trial and error to see which ones exactly need to be shown.]

Before I figured all this out, I installed Reset Doctor. Some of the other system crashes I was getting (I'm listing these for benefit of those searching the board for these terms):
"SystemCompatibility.c,Line:64, Invalid card #"
"Fatal Exception"

Other issues that have been solved by showing those built-in apps:
Quick Keys and Favorites work now. Green key didn't do anything before, now it dials as it should.

I hope by this thread I've given back to the community, 'cause you all have been so helpful to me over the years!