VESA driver hsync config problem

["Xavier Toth" <txtoth gmail com>]

For awhile now I've been struggling with what is probably a Vesa
driver issue related to but different from Fedora Core bug# 10238. I'm
running the latest X (7.2) under FC6 in a Parallels VM on a Mac and
the server won't start unless I specify the HorizSync in the Monitor
section of xorg.conf. I dug around and found references to
vesa-1.3.0-range-hack.patch which I applied but this made no
difference.
My group is putting together a livecd for demo purposes and the
xorg.conf generated by system-config-display (FC6) doesn't add a
HorizSync so X won't start. Hopefully someone will have an idea how to
fix this otherwise I might have to hack the config to add the
HorizSync as an interim solution, any thoughts?