Internet router/TV is interfering with FM reception

I have my stereo receiver (and several other components) in the same entertainment center as my TV. The internet router is placed behind the TV. The stereo receiver has a regular FM dipole antenna (300 ohm) hooked up to it, actually I have it tacked to the back of the entertainment center in its normal "T" shape.
When I have my TV on, the FM reception is really lousy -- I can only get one FM station which probably only a few miles away. When I turn the TV off, I can get many FM stations from as far as 70 miles away.
Is there anything I could do to get good FM reception with the TV on, maybe hook some kind of filter between the antenna and the receiver? I thought about a cheap FM signal booster but from what I've read I'd probably just be boosting the noise along with the FM signal.
Maybe some kind of outside antenna would solve the problem but that isn't really practical for me. Also the router still might interfere with its wiring when it comes near it.