About a month ago we had a lightning strike take out the cable and broadband, for a couple of hours. The cable came back, but the broadband did not, until I did a hard cycle on the cable modem and router, days later Obviously my IP got dropped in this case. I am unsure if this is the case of late though.
why dont u connect the modem to the pc..just for a day or 2 to see if you have the same problem. then you will know for sure. i have the same router at home. havent resetted in over a year!
Cable modem is, get this, by the TV and the PC is in another room in the house. If I had 100' of CAT 5, I could test your hypothesis.
seriously, test the modem using a friend's laptop or cart the pc out to the outlet. if it's not the problem, install DD-WRT for firmware. rock solid.
I've had a problem with mine for about 8 months now.. I can ping a website from the router but cannot ping from my computers(2 desktop, 2 laptops) I have to reload my configuration file every time it happens.. It's annoying but I too cheap to plunker down another $75 dollars for another modem.