Router & Internet Connection PROB

Ok I have a really annoying problem, when I first turn my computer on my router & network connection just goes on & off, on & off for about 10-15 minutes, it's not a weak signal & It never did it before on my old computer. I have to keep refreshing or just wait till it finally gets a connection, not sure if something is conflicting. I have a belkin wireless router, with a USB sensor. I have broadband & my router goes through a Motorola USB cable modem. I run AVG virus software & Sygate Firewall, everything is enabled that needs to be in sygate as far as I know, I get a popup that says ntoskrnl.exe has been blocked even when I enable it. My computer is brand new & all I installed was the router software, not my ISP software. It found my old WPA connection so I connected, once I'm connected it is fine but I always have to mess around 10 minutes before it will connect & it's really frustrating! Any1 got any possible idea why this could be happening & what i can do to fix it? when i run IPCONFIG /ALL command it says: IP routing enable....NO could this be it?
I really don't know what I'm missing!

Please help