Waves On My Plasma

Hi, I really need help, I have the philips plasma. now i see these waves on my tv. they go back and fouth from left to right and right to left. it has something to do with the electricity. but i am really not sure. i have since changed the outlets and bought a new power cord and still nothing. i was hoping if anyone can help me with this problem, also if any one can tell me what is the best powercord to use for the plasma. any help will do. thank you
Are you watching Discovery Channels "Oceans of the World"? Change channels and the waves may go away...

Seriously, since no one else has responded, have you tried a power line conditioner? If you are sure its a power line issue, I probably would have tried that before swapping out the outlet. If that doesn't work, you might try asking the plasma gurus on www.avsforum.com. Those guys live, breath, and die video.
Thank you for your responce, i have a Richard Grey 400 on it, i have also called philips which was the biggest mission and they had no idea what so ever. the best thing they could tell me was to bring it in my self and then they will charge me $500 just to look at it. i would like to have an idea whats wrong before i pay $500 for some one to look at it to tell me that it has to be something else.
i will check out that websitem and once again thank you.
also do you know what power cord will be good to use with a plasma tv. at the moment i am using a sonic horizon hurricane powercord and it made a big diffrence more then the power cord that came with the unit, any help will do, thanks alot my fellow audiogon member.