Displays and Projectors : Please HELP!!!!

Please HELP!!!!

I have a mirai HDTV but for some strange reason, whist watching tv through my virgin box, it keeps swapping between PAL and SECAM which ditorts pic and sound until it has done so. It wouldnt bother me if it was once in a while, but its every 2-5 minutes.
Is there any way that i can stop this from happening???

Think of a movie in the way it was intended....entertainment