Yes I did similar to my old AGP FX6200 card years ago.. it kept doing goofy things, so I reseated the (passive) heatsink with some new grease, and I installed a small 2" fan over the heatsink. Completely cured its issues. To be honest, I think AH2 was just a bit much for that card (even back then) but I played AH with that card for a couple years anyway.
Now that I think of it, my brother uses that card in his PC to play WOW today...