hello !
glad to see I'm not alone with my 945GCM-S !!
anyway, switching to 'compatible' mode can't do the trick for me, since I've got 4 SATA HDs and 2 IDE optical drives, which I want all to work.
so I'm trapped with the usual IOATAFamily KP, netkas' PIIXATA or not ...
if I put my 10.5 vanilla IOATA, it works in x86 mode, but I have to forget x64 until it gets solved.
using a patched DSDT.aml too (using 1.20 official bios), for boot hangs without it (in 10.5 too) ...
do you get the internal ethernet controller to work by the way ?
edit: after more researches, it might related to my amount of RAM (4 Go) ; investigating with maxmem flag ...