I own my n900 now more than 1,5 years and so far had no problems at all. However now a strange issue occurred. In the menu my phone app is set to work only in portrait mode, but now it works only in landscape. I think it’s because it thinks that physical keyboard is open (proximity sensor is also not working when phone app launches). Is there some way to check if it is a hardware or software problem? Or can anyone help me to fix this issue?