Internet (cable) problems

I have cable internet, and it used to be shared. but recectly the computers started acting up and the net stopped working. So we called the cable company and told them it wasnt working, they told us how to get it working but it was no longer shared. The modem is a Toshiba pcx2500 it has a spot for a CAT5 cable and USB to attach to the computer. So we attached both to the modem (the CAT5 cable going to a [switch] and it worked fine. Until recently, now it the modem seems to be getting picky. It either wants USB or the CAT5. It wont take both anymore. So again, we called the cable company and they said that it wasnt possible to do it without a router. But we've done it with a router. Does anyone know how to get it working correctly again?

As I sit up in my bed looking at all the stars, I begin to wonder... WHERE THE HECK IS MY ROOF!?

Sorry, typo. I meant to say that we've been able to do it WITHOUT a router. Sorry.

As I sit up in my bed looking at all the stars, I begin to wonder... WHERE THE HECK IS MY ROOF!?

Well, we called them about it before. They said that it should work and all we have to do is plug it in, as far as I know it wasnt any promo thing, because it lasted almost a year; I dont think it was a mistake either because we called them and told them we had done it. And they still didn't do anything about it. Dont you think they would have done something earlier?

As I sit up in my bed looking at all the stars, I begin to wonder... WHERE THE HECK IS MY ROOF!?