problem with shaky display

[Slogun]

Bought a Sony 19" HMD-A440 a month or so ago. I've noticed that the upper left and lower right corners of the screen seem to shake or vibrate. It's a little annoying.
Do I have a bad monitor or does it require some sort of adjustment?
I have a GeForce3 vid card on that machine with updated nvidia drivers.

 

[AkumaBao]

Have a speaker or modem next to the monitor? Have you tried degaussing it?

 

[Slogun]

I tried degaussing.
Could be the speakers. Have 4 cambridge speakers there, will try moving them and post the results.
Thx.