I have machines with PS/2 ports (which cannot be turned off in the BIOS) with which we use serial mice. The X-based installer refuses to start in this scenario, as it assumes if there's a PS/2 port that there's also a PS/2 mouse, instead of probing for serial mice as well.
What's happening? Is X starting and the mouse not working, or is the server failing and returning you to text modes with error messages on the screen?
The server's failing to start. The only messages I get are: Probing for mouse type <wait a bit> X startup failed, falling back to text install there are no temp. files from XFree86 in /tmp afterwards, no messages on any of the other consoles, etc.
This issue is resolved in the next cut of the beta tree.