Flashed the x.10.08.04 radio last week after getting patchy signal for no apparent reason. I would wake up in the morning to find my phone saying "No Service" when I went to sleep with a full HSDPA signal. Switching to Airplane mode and back would sort it out but not very satisfactory.
After a few panicked moments where the phone was stuck on the white splash screen, I rebooted into recovery, did a cache & factory data wipe, and tried again - success!
Signal seems much better again now, thanks to all who contribute