I just did this recently, had the same problems.
You need to :
1: Download and isntall the SME development tools and source code (search the forums).
2: Download netatalk from sourceforge.
3: Download berkleyDB+ patches from sleepcat
Build and install BDB libs, then build and install netatalk. Reboot, voila.
I don't know of any rpms, I had the development tools already intalled on my sme to build LVM, don't remember where I got them. Just read the readme's and everything should be ok. If in doubt, back up your data+config first or experiment on a test server.
L8R
Mogamat Abrahams
mmaxx at webmail dot co dot za