That's very surprising!
I was half way expecting those symptoms with my keyboard & mouse, which are blue tooth (Logitech), but they work flawlessly. My BB is always sitting on the edge of the mousepad.
When I hook up my BB to my PC, it sits right next to the BT receiver(OK, about 4 inches to the side), and again, no problems at all.
Is your receiver going through a USB hub, or plugged directly into a rear port?