Question Problem with hanging up if i get voice mail

Im using slimkat rom and ive noticed this issue if the call goes to voice mail then the screen wont turn on so i can never hang up.
i press the power button and it flashes on for half a sec then goes immediately dark again. home button also does the same thing.

Only way for me to end calls if i get voice mail is to pull the battery.

Anyone else noticed this issue or have suggestions for how to fix it?