Wrong refresh rate?

Hi gang,
Im having a problem with the 1280 x 1024 resolution on my monitor. any other resolution works fine. when i change it to 1280 x 1024 I get wavy flickering semi round lines on either side of the screen (kind of looks like a faint contour map). my first instinct was that the refresh rate was wrong so i set it high and low and no luck. its currently at the supported speed of 75Mhz. again it works fine at any other resolution, and is a supported res.

Any ideas?

Samsung SyncMaster 955DF
ATI HD 3650 1gb

Did you install the monitor driver or are you using Native drivers?

If you need the manual, try here;

http://downloadcenter.samsung.com/content/UM/200306/20030618135144015_BH59-00335J-05ENG-AN19JS.pdf

opps,
yeah thats a critical piece of info. I am using the monitor driver, latest one.

I have never used an ATI card so I'll bow out here after saying that you should ensure the GPU is talking nicely to the LCD, ie, refresh rates etc.

I imagine ATI has a settings panel like nVidia where these things are displayed/controlled.

Jeez, that's an old monitor.. What you'll probably find is that in reasonably short order other resolutions will start screwing up too. I found that with an old 21" Hitachi I used to have a long time ago. One resolution went, then others. Finally it died altogether.

If it's an old monitor, it might just be screwing up at that resolution... don't ask me why but I had a monitor that worked great for a while, and then started to do something like this.
I got rid of it cause it heated up my room too much anyways and bought a nice LCD... no more problem lol.
(I also have a 100 pound paper weight in my closet lol)