I assumed the other apps open overloaded the processor and the mediabar just didn't like it, however it has stuck open a few times but today when I had a few more apps open was the first time I needed a reboot. My question was asking if anybody else had the same issue, if nobody else has it must just be my N900. Until I have just checked I nver realised it was a button I alwauys assumed it was the proximty meter before today!! Anyway It does make you wonder why Nokia ever did use a seperate button just for this one shortcut when your idea is far simpler.