I'm sorry to hear that you're having this issue.
I can't exclude the television, of course, but you might check with your router's customer service to see if there's something that is causing the connection to time-out when connected to the TV. In some cases, a simple setting can be causing this symptom.
A few months ago I purchased a Samsung LN46C650 tv. I chose this tv over the lower models of the same size because of the finance option at the location I purchased it at. The internet option sounded good but was not one of the selling points. In addition to it I have a Sony Blueray player, which I normally use for streaming netflix or music, however I would like to have my TV set up as well.
Now, the problem is, the tv will not stay connected to the internet. I can get it to connect. I can get as far as loading a Netflix movie or starting to play a song on Pandora, maybe a minute into either, maximum, then it tells me there was some connection interference or lost connection or something.
I use the exact same internet cable on my blue ray player, and Netflix and Slacker Radio stream flawlessly, so I know its not my cable. I dont know if its connected but several times when loosing connection I returned to my computer to diagnose the problem, and found aim signed out after loosing connection. This is not normal, so I am positive its somehow related to the tv. I dont know how, both my computer and tv are using wired connections through a router in the basement.
My router is a D-Link DI-634M, which has never given me many problems over the years, using multiple wired connections as well as a steady wireless connection to my PS3.
I also have a Linksys WRT54G I could plug up and try to see if its the router.