HP laptop problem

A friend of mine and I happen to have nearly identical HP laptops (a ZX275and a ZT1000) which share an identical, maddening problem. While running graphically demanding software applications (games of course) the mouse will "disconnect" at regular intervals. Depending on the game, you sometimes hear the "device disconnect" sound, the mouse will stop responding, and after an indetermenent amount of time, the "device connect" sound plays, and the mouse starts working again. (mouse is optical usb in both cases, before you ask we have tried mechanical usb) We're both working with HP tech support, but they seem to be out of their depth. And of course we're running third part software and aftermarket accessories. Both 'puters do an otherwise excellent job of running said applications, I.E. frame rates are outstanding, game runs smoothly, but this mouse thing is driving us both nuts. Seems to happen more during lan play, but no hard data to back that up. Any ideas?