Interesting, could this be related to the fact that Bluetooth never autoconnects to my car stereo, instead I have to restart Bluetooth and/or connect manually? I'll try disabling wifi and seeing if it auto-connects
Check your free storage space, and consider that it might not be downloading to the place you expect. Mine did that where the progress bar moved and then just inexplicably stopped and gave up until I cleared out some space.
I had exactly this issue on the stock ROM, pain in the arse. Haven't experienced it on the Cyanogenmod based ROMs though, although I understand that's a lot of hassle if you don't want the rest of what goes with that