Ah the endless debate on graphics cards. Just more memory alone doesn't mean that a a card is going to perform better. You really have to read up on benchmark testing for video cards to get a good idea on the capability performance wise. I recommend
this site for comparing computer hardware.
I don't mean to say that what thegreatone has said is absolutely wrong just that I don't think his graphics card is holding him back. Heck I have an old GeForce 3 card with 64 MB ram and I run World of Warcraft at good quality and regularly 50-60fps. Where as my roommate with a similar system to Codine runs at ~30fps with the same visual quality settings. His card has 256MB of ram and our load speeds are the same. *Shrug* I would just contact the game developer.