FC6 and AMD64 CPUs?

[Jim Lowman <jmlowman@xxxxxxxxxxxxx>]

I have tried, without any luck, installing FC6 on two of my AMD64-based 
computers.

Computer #1 is an HP m7640n that is a few months old.  It has a 
dual-core AMD64 X2 5000+ CPU, and an nVidia GeForce 6150 LE display adapter.

Computer #2 is one that I assembled, with an AMD64 4200+ CPU, and an 
nVidia display adapter.  This box has FC4 on it, with no new hardware 
installed since that install.

The install (AMD 64-bit version) stops dead after identifying the video 
card, in both cases. The "X" comes up and that's it.

Someone mentioned furnishing parameters when installing on a box with an 
AMD64 CPU, but I can't seem to locate them.

I'm about to pull my hair out, what little there is on top.  Any help 
will be gratefully appreciated.

Thanks in advance...Jim