So, this "flashing light" scenario has happened to me several times on my 8800c and the way I'm able to fix it is by the following process:
- remove the SIM card, MicroSD (this seems to be the culprit), and battery.
- let it sit for a minute
- only insert the battery and let it fully boot
- power it off
- put the battery, SIM, and MicroSD card back in
- let it boot normally

Hopefully this helps... usually I get into the "flashing light" scenario when I've made changes to my account and/or recently dropped my phone. Honestly, I've never been able to completely put my finger on it and not sure if all the steps above are necessary but it seems to do the trick every time.