Stupid question I know, but did you A) manually start MPTray.exe or B) reboot the machine, which then autostarts MPTray.exe, also do you have UAC enabled, that may block.
Hey again... yes i have tried to manually start mptray.exe but nothing happens, and i have reboot the machine, and disabled uac. BUT in task manager i can see mptray.exe... but cant open with the green button anyway...