Weird Wi-Fi problem

Okay anyway, I have a Linksys Wireless router, It was a little shakey setting up, but after a few minutes of frustration I managed to get it running. It ran fine for about a month. Then my internet stops working, since I could still see and acess other computers on my network I figured that it was adelphia. Anyway three days later I tried a direct connection to the internet, and it works fine. Now however I cannot acess the internet on any of my other computers. I've already tried repairing the network countlesss times and re-starting and re wiring. Apparently the router cannot communicate with my cable box. Any suggestions?
Thank you in advance.