USB Devices Lag

Alrighty, here's my predicament.

I have been trying everything to reduce the input lag on my Rock Band drumset for use on my PC. Whenever I play my rhythm games there is a noticable lag on hits so it throws me off, and keeps me from actually playing properly. I've tried the polling rate fixes but that did nothing.

I was wondering if the number of USB devices plugged into the system makes a difference. I have 4 in the back which has my Razer keyboard (2 plugs, one for the keyboard and the other for the USB port on the keyboard), my mouse, and a printer. I have another 3 in the front, connected using the front side USB connectors on the mobo. If it does, would buying a dedicated USB controller card help solve the problem like how it would for sound and video cards or not?

Still the same 13.47 ms delay on my Input Lag test. I've tried solely using PS/2 devices and same thing.