OTA Gingerbread 2.3 update fails to install on DroidX (rooted stock Froyo 2.2.1 / unrooted back)

I was trying to install the Gingerbread (Android 2.3) OTA update available from Verizon for my Droid X. However the update ALWAYS fails to install. It downloads fine, pops up a message saying that the update (**4.5.605.en.US**) is about to install and needs a reboot, then reboots when I OK it. **After the reboot, it pops up "Update Status: The Software Update Failed" error box.** ---------------- My only possible suspicion as far as the reason is that my DroidX is rooted via z4root - I posted a separate question on how to un-root it ( https://android.stackexchange.com/questions/15760/is-there-an-easy-way-to-un-root-android-2-2-on-droid-x-rooted-via-z4root ) in case that suspicion is true. **UPDATE** - I unrooted using latest z4root version. The problem with OTA was NOT fixed.