Got cable internet, but get disconnected

[DWarrior]

I just moved and got cable internet set up from Optimum Online. Standard issue Motorola SBV5120 SURFboard. I have a Linksys WRT54G 8.0 router.

Normally the modem has 4 green lights on: Power, DS, US, Online; and an orange light: Link

It seems as though every 10-15 minutes the Online light goes off and US starts blinking, and I lose connection. If I turn the modem on and off it goes through the reconnection process and then works fine again.

Any ideas?

EDIT: called up the company, they said it's probably a weak signal, so they're having their tech repair guy come later to look at it.