It seems there could be some issues with the release of Guitar Hero II, or at least the X-plorer guitar itself. Gamers all over the internet are reporting issues with the whammy bars.
Luckily there are two versions of the guitar and the issue only affects one of them. The type you should try and avoid are the ones with the pedal jack next to the power cord, ones with the pedal jack on the bottom of the guitar are fine so far.
As for the problem, apparently the whammy bar just stops working all of a sudden. Bear in mind that the issue is not aeffecting everyone with the problematic type of guitar, but at this story gathers momentum over the internet, more gamers are coming out and posting that they have issues.
How about you?