BTX Halted on 6.1 but not 5.4

[Chris]

I was trying to build a test machine so I could run something on 6.2  
PR and keep abreast of the changes without updating a server I've  
pushed a little further than I should have ;-). I had an old Compaq  
Presario Athlon 900 that wasn't doing anything so I attempted to  
install using the 6.1 ISO. I found I could not get past a BTX Halted  
error even after disabling everything in BIOS that can be disabled,  
disabling ACPI and removing all the cards but the video. The board is  
quite proprietary and has no configuration options whatsoever.

Researching this, I found several possibilities but none applied and  
I concluded there wasn't much that could be done to work around the  
problem. Then when I was about to give up, I noticed I still had an  
old 5.4 ISO in my stacks of disks. I popped it in and it sailed through.

My question is, is there a good probability that if I install 5.4 and  
cvsup to RELENG_6 that it will work. I didn't see anything that  
actually gave a clear definition of the BTX Halted error and am  
wondering if I put in 5 or 6 hours on this box, does the BTX Halted  
error provide any indication that it may have an issue anyway beyond  
just sysinstall? The cost of a mobo and CPU for a test system will  
end up a pretty cheap alternative if the hours start adding up.

Thanks,
Chris