[Vermin]

Hi. I have the PC version of Guitar Hero World tour, and I've connected two GH2 Xbox 360 USB (wired) guitars to my PC.
I want to be able to play together with a friend, but for some reason, my second guitar isn't recognised by GH. In Control Panel, it doesn't show any problems, and in Frets on Fire, both guitars work perfectly.
In Guitar Hero WT, the second guitar doesn't do anything, and at multiplayer, I can only select one guitar, and you can see three guitars.
Does anyone know how to fix this?
It seems that only the first guitar I plug in works.
It doesn't matter which of the two is plugged in or which is first, but it will only be the first guitar that works. It doesn't matter in which USB port the first guitar is plugged. It will work in any USB ports, so the ports aren't broken.