Hi there.I'm new to this forum and am in need of advice.When playing any half decent game(this happened on quake4)the screen gets very jumpy (like a dvd player on step feature).My friend says my graphics card is to blame.I have a Dell3100,pentium4,512meg ram,2.8GHz processor,intel82915G/GV/910GL graphics card.Is this good enough.If not what do recommend?