Well, I have a rooted DroidX. It was fine before the update to 2.2.1 since then it reboots every time it detects updates. I used z4 root to root my phone "one click" style. The only reasons I rooted for was to hide ads via an app called adblock which modifies the hosts file, and disabling stock apps via renaming the apks to apk.bak. I do not over clock or run custom roms etc. I don't have any reason for all that garbage, and to be honest, don't know what all the fuss is about. I run Launcher pro - Paid version. The apps that I have disabled are as follows:
skype mobile (hate skype deeply)
voice commands (what a POS)
voice commands is the stock motorola voice shiz. and boy is it shiz. It's the only vendor app I've disabled.
When I upgraded I unrooted the phone, removed z4, rebooted the phone, ran the update to 2.2.1, and then simply re-rooted it.
One caveat is that I'm not absolutely sure that the phone started rebooting after the 2.2.1. What I mean is, I'm not sure that's the catalyst.
Also, it has rebooted a few times without detecting updates immediately on start up, and it has also detected updates WITHOUT rebooting the phone once or twice.. But an overwhealming majority of the time, it finds and update after spontaneously rebooting.
I'm thinking theres some system call that causes a kernel panic or something along those lines, but have no idea where the logs are.
Any help would be appreciated.