Actiontec Rev I Internet Light blinks constantly

I've had a rev I router for a few days now and the Internet Light on the front blinks nonstop, 2 or 3 times a second, even with wireless off and no cables connected except the coax line. Is this normal? I'm pretty sure the Internet Light on my old router was solid with an occasional blink. I haven't noticed any issues but was wondering if this is normal. Thanks!