Ive got the same problem. It seems like the update is running through, but afterwards it's still on 384.5. mine is a T-Mobile router that I've converted. But it worked fine for the past 10 updates or so.
I just recognised that my overclock settings don't stay after a reboot. The CPU frequency doesn't change at all, but there is an increase in Bogo mips. So the command is working...somewhat.
I've been on on 380.2 before and everything was working fine. Is there a new command I'm missing?