Unable To Do More The 2 Button Presses

So apparently i'm no long able to do any more than two buttons at a tie when using emulators. Obviously this is a software issue not a hardware issue since my keyboard has not changed since the last timme I was able to use more than two buttons. Is there anything else that might be limiting the number of accepted keyboard button presses aside from the keyboard itself, and how would I go about increasing this limit?

Also this guy's problem is similar as well

http://superuser.com/questions/192200/keypress-limit-anomalous-problem/1089295#1089295