BB Storm :: 9520 - The Screen Shuffles Between Portrait And Landscape Mode?

Sometimes, during incoming calls, the screen shuffles between portrait and landscape mode. And when I press the green accept button (in either mode), the ring tone stops and after a second or so, it starts to ring again. And obviously, during all this, I am not able to receive the call using the screen button.I know the simple solution is to use the physical green button at the bottom but would still like to resolve it. Is it a genuine problem with all bb storm 9520s? Is there a fix to this by changing accelerometer settings or something?