At the point where you see the grub splash screen, press a key to interrupt the boot process. Now that it's halted, press 'a'. That will allow you to add a kernel boot parameter. Add this to the end of the line:
You know man YOU ROCK !!. Did the ACPI=OFF after loading into GRUB and alls working fine Sound internet and all.
I just configured internet on my FC5 and am replying to you.
Know do i have to do that bit every time I load into linux... or is there a permanent solution
Edit /etc/grub.conf and find the line that says "kernel /vmlinuz-blah-blah-blah". At the end of it, just add "acpi=off" and it'll boot that way from now on.