If you are having panics looking like this, try replacing your IOATAFamily.kext with the attached one, and let me know if it fixes the panic. I have gotten access to my PATA drives on a BadAxe 1 board using this kext.
Note that this is not the IOATAFamily from 10.5.8 as described here, it is compiled from patched Snow Leopard source code. The source is available from Apple here and the small patch I used is also attached to this post. The AppleIntelPIIXATA.kext is also included in the PlugIns folder of the attached kext, but it is unmodified.
Edit: replaced the suspect .tar.gz with a .zip file
Edit 2/4/10: Apple have fixed the bug in 10.6.3, so this patch isn't needed/useful anymore for 10.6.3+ systems.