M80's are video shielded and you can place them as close to the TV as possible. However, it has been suggested at times in this forum that they should be around 6 feet apart to improve the sound stage. They should also be at least 18" from the back wall. You can experiment on speaker placement and choose the one that sounds best for you. At least you do not need to worry about video shielding.
VP150 is also shielded but some TV's could be more sensitive than others. I remember some VP150 owners who encountered the same problem and solved it the same way you did.
