I'm using a SIS 5598 video card I'm upgrading from 6.0. The Redhat logo screen is oversized, then when the language page comes up, all the choices are blacked out. Note: A similar thing happened when I tried to upgrade X to 3.3.5
*** Bug 8319 has been marked as a duplicate of this bug. ***
You should also be able to use text mode to complete the upgrade ... the SIS 5598 is known to have issues with XFree86 3.3.6 ... (see http://www.redhat.com/support/hardware/intel/62/rh6.2-hcl-i.ld-10.html section "10.40 Tier 3 Video Cards") ...also, there is a XFree86 site that has more information (note it is not a Red Hat site): http://www.xfree86.org/3.3.6/SiS.html