I was having a problem with my cramped, overheated Dell Inspiron computer case in which the graphics card (GeForce 9800 GTX+) and the CPU (Q6600 Quad Core) were too close to the on-board network card. When I would get into some serious FPS gameplay, they would heat up and cause my connection to get all wonky.
Solution? Buy a bigger case with more room, more ventilation, and more fans. MOOAAARRRRR!!!11elevnty
Bonus: It has pretty lights. Yay.
The new case isn't the best, but it serves my needs. It has front and side 80mm fans, plus a HUGE 120mm fan in the back. Here are the pre-requisite poorly taken pictures.