laptop-vga-32" hdtv

got a vga cable the other day, plugged it in, and it connnected to my tv fine, except it had a subtle wave like effect through the screen, it took me a while to find out what was causing it, but i found that it happened when i plugged the power cable in, when its on just the battery, it runs fine, but as soon as i plug it it, it goes with the waves, could someone please help

this is the laptop i have, just in case it helps

play.com/PC/PCs/4-/4026081/hewlett-packard-pavilion-G6060EA-Athlon-64-X2-TK57-1-9GHz-2GB-160GB-DVD-SM-15-4-Vista-Home-Premium-Laptop-Notebook/Product.html

Did you buy a nice thick VGA cable?

Could be a shielding problem.

What type of laptop? Does it do it with our TVs?