I seem to be running into a similar, if not the exact same issue. I've seen a few articles stating that this is likly due to a bug, but I was hoping that you could confirm what version you were running prior to IOS upgrade and what you're running now...
I had the same or a similary issue. A CP-8841 w/ flashing red light and prompt login with 1. Service domain, 2. Username, and 3. Password.
Later found the the voice vlan was not configured on the port. Configured on connected switch:
conf t
int gi XX...
