[Update] Definitely hold off on updating Guitar Hero II with this patch. We've received reports of the infamous "blinking red light of death" after installing the latest update. For more information, please see our latest news story.
It was reported last week of numerous problems with the Whammy Bar on a significant number of the X-plorer controllers for Guitar Hero II. This was initially chopped up to be a faulty controller, but according to Activision it was a software glitch.
As reported on the official Activision FAQ this morning, a software update is now available over Xbox Live for those experiencing problems.
I am having problems with my whammy bar in Guitar Hero II on the Xbox 360.
We really appreciate you bringing this to our attention. A title update for Guitar Hero II for the Xbox 360 is now available on Xbox Live that should resolve the situation where input from the whammy bar was not always recognized. Downloading the update should resolve this issue for all Activision Guitar Hero branded guitar models. We are very sorry for any inconvenience this may have caused.
We've confirmed that the update is available on Xbox Live, and have heard reports that it does indeed correct the earlier issues with the whammy bar on various models of the X-plorer controller. Reports have just surfaced that the update is causing some Xbox 360's to fail. Hold off updating until you hear more.