With Fedora10, (and even XP and UBUNTU), the resolution and vertical frequency settings are such that the display window for the settings of interest to me are displayed squarely between the physical borders, full width.
Even so, it is a perfect fit for 1024 x 768, 1280x960 and 1600x 1200 with the F10 X version.
With the live CD version, I have the following problems:
Monitor NEC Multisync E100+ Video Card ATI hd3850 (256meg) with default radeon driver
1600x1200 -- right margin OK, missing 8 cm (1/2 inch on left) with refresh at 75.
1280x1024 -- too narrow (1/2 each side short)
1280x960- -- right margin OK, missing 8 cm (1/2 inch on left)
1152x864- -- too narrow (1/2 each side short)
1024x 768 -- Perfect fit.
But with F10, the 1280 and 1152 modes are also perfect fits on the display with Fedora10 and Ubuntu.8.10
X settings need to be tweaked to what F10 supports for the above sweep information