Thank you very much, it worked for me too fortunately. Doing this seems dodgy sm a couple posted about problems in various topics about flashing, recovery stuff, etc.
Thanks but unfortunately after booting successfully into 2.2, setting up my accounts, APN and receiving email, the next reboot after a shut down stays at the M logo.
edit:
It seems to boot into the system, I can hear the notification of USB connection and I can get into adb shell too.
It also turns off the screen automatically, but I can only see the M logo on black background, not the lockscreen.
edit2:
After adb rebooting with the USB cable left pluggefd in, it boots normally. I think some other users have reported this problem already, maybe related to bad battery data?