I have a droid x with 2.2 froyo on it and i have been manually pulling down the ota update for gingerbread. So it will download the update, and shut the phone off and when you do the startup point for the installation, it will get about half way through installing, then boot up back into froyo and say update failed.
What i've done to troubleshoot,
Battery pull
cleared cache
cleared browser cache
factory reset
and i'm stumped, i have no idea why it will not install. i have plenty of space for it in flash drive space.