reading around and there seem to be a slew of suggestions
to start simply, how about turning off USB legacy support in the bios - people report that this has resolved install problems for a number of distros and USB worked anyway with no additional steps
if you've already tried that, then there are a few commands you can pass at the boot prompt when you start the install process:
nohotplug
nousb
noapic
noapci
people report varying degrees of success with different combinations of these on the same/similar mobo - caveat: some people say that the install will go, but then the onboard networking will need post-install tinkering to get it working
finally, you have the option of making your own kernel, but you may not want to go there yet - one way to make this as painless as possible is to install mdk / rh and then open up the /var/log/messages from the install to see what hardware was detected, also lsmod to list the modules being used - make a note of this info and then try building your own under slack
hopefully someone who has actually succeeded on the same mobo as yours will be along in a bit, for now good luck