I have my user directories shared in exactly the same way on my intel iMac and my PPC Mac Mini. Since originally upgrading to Leopard (I now have 10.5.2 and no change), the directories are in fact both shared, and I can access them from both machines, but:

My "username" directory shared out on my Mac Mini will show on my iMac desktop. My "username" directory shared out in the iMac will not show on the Mac Mini desktop. It is in fact shared, and I can access it from Finder, but can't see it on the desktop. Any suggestions? Thanks!