I just tried installing CM7 GB on my droid 2 running stock verizon froyo. My phone was rooted with z4root and had clockwork installed. I created a backup. I then downloaded CM7 GB through ROM Manager, proceeded through the install, but when the phone rebooted I'm stuck with a replay loop of the CM7 animation.
Booting into recover (pwr + up arrow) lands me in the stock recovery screen, not clockwork mod, so I don't see the option to restore a backup.