I remember I bought some GSkill RAM when I first put my system together and I was having a hard time running any games.... I was being told that there was a video card issue... I tried to change my PSU (as I assumed it wasn't enough wattage) only to FINALLY find out after 2 years that my RAM was slightly out of sync causing the video card problems.
Every manufacturer releases a list of memory compatible with their products. It sucks buying memory that's not compatible, but at least now you know that a little research can prevent a ton of anguish.