I have just installed ATi drivers (for openGL support.) Now the display only takes up part of the monitor (black borders.) This would be fixed when I change the Hz of the display to 75. Now I only have the option of 85Hz in my Screen resize and rotate. How do I get it back down to 75?

Get yourself a copy of xvidtune. It probably comes with your distro. Run it from a terminal in your Xwindow environment.
It allows you to make changes to width / height and the like and test them.

When you are happy with the display, click "Show" and it will print a modeline in the terminal window you started xvidtune in. Copy this to the "Monitor" section of your XF86Config-4 or xorg.conf (you'll see from the other entries just what the format should be) [Good idea to make a copy of the file before you edit it!]. You may have to comment out some of the inappropriate modelines by placing a # at the start of the line. Then restart X (by logging out, then in again). You should be fixed.

HTH

I get an error message:

Sorry: You have requested a mode-line that is not possible, or not supported by your hardware configuration.

I don't know what I'm doing here. Maybe it could be a problem with entering in bogus results? I can't run the Test.

I do not know what you are doing here!

When are you getting an error message?
What is giving you the message?
What did you change or do to get this error message?
What "Test" can you not run?

Please be a lot more specific!

You can modify the xorg.conf file, here is link: http://xtiming.sourceforge.net/cgi-bin/xtiming.pl
simply input "Visible Resolution" and "Refresh Rate", click calculate modeline to will give you the desired modeline. Add the new parameter to xorg.conf in "monitor section", restart X.

Don't know if this will help you but worth to try.

I just installed suse 10 and i have the same problem here,i visited the xtiming page,put in 1280x1024 , 30-111,50-160 and 85Hz for my LG F900P
Then i copied the modeline in my xorg.conf,but wheni changed it from the control panel settings my screen had a black border on the left side.It was moved to the right,(i couldnt see the time in the taskbar).

Where do i find xvid tune?