LCD Monitor Issues Help Please?!

Alright, After getting the Samsung Synmaster 906BW 19inch Wide Screen monitor the screen seemed to be a bit wavey. Almost like an old tv with a bad signal. I had thought it was a power issue and also was told it could be. So i had switched the outlet and wired it to the best way as my friend told me to (Friend is a master electrician). So I did that still seemed a bit wavy. I ran an extension cord from the monitor to another outlet in my room. Not was wavy but still a bit wavy . Now, It is an analog connection so im going to pick up a digital cable and try that. Is it a faulty monitor? Is my video card going bad? Why would the picture get better when i run the extension cord? Really confused and stumped . Please help! Thank you, IceCold