G1 Misbehaving -- can I (should I?) reinstall donut? I have an unlocked G1 (b/c I am stuck with an AT&amp;T contract) that recently started to do a lot of weird things all at once. Most notably, it rings but does not show the caller or allow me to pickup. The home key no longer does anything, and when I hold down the power key I see only the "power off" option -- no airline mode or silent mode.

I can make calls just fine but this is obviously an issue. 

I've managed to get root on the phone (via UniversalAndroot) and BusyBox and i've been reading this: http://gailly.net/android/android-tips.html but I'm not really sure where to start troubleshooting this. I think I need a development OS to actually run adb root. I'd like to at least try installing or upgrading my OS.

Am I barking up the wrong tree? This is my only phone.
I'd actually recommend upgrading past Donut, since there is a great custom ROM community for the G1.  For example, this looks like the best Froyo ROM for the G1, but you can look around XDA's Android Development forum (specifically the ROM Bible thread) if you want to find out more first.