What a friggin' nightmare - it took me 4 hours to resurrect my bricked, boot-crazy Bold! If you are on AT&T, and were foolish enough to do this upgrade (uh, like me), here is how you can recover:
1. Re-install .314 (or whatever was your last OS version)
2. Remove the vendor.xml file, as usual.
3. When the red light goes out, and it starts booting up, start AppLoader, and click the checkbox for auto-locate. (NOTE: You cannot use Desktop Mangler for this, because it will not retry as frequently as you can make the AppLoader retry.)
4. When it finds the device, and puts your Bold's PIN in the dropdown box, click Next>> to initiate the install.
5. Don't be discouraged if the Bold reboots again, or seems to 'hang'. Let it work.
6. Keep trying until it works, which it will, eventually.
7. Uninstall v188.8.131.528, and never speak of it again.
I had my Bold set up good too, and now Viigo will not install from App World or their website. Dang it!