OK, I managed to figure out how to change the mount type within the kernel. This intercepts any calls to mount hda4 or hdc4 and changes the mount type from ext2 to ext3. The patch is at http://macgeek.dyndns.org/empeg/ext3/mountHack.patch.gz and a new kernel with this change is at http://macgeek.dyndns.org/empeg/ext3/zImage-2.2.17-empeg-ext3-hijack.gz

So... that should be everything needed for anybody interested to get ext3 working on their player. I have been running it for a couple of days now and have done at least a dozen syncs with no problems. It rocks!

-Mike

p.s. to mlord. You can ignore my private message, as you can see I managed to figure it out.