I have slightly modified the PrinterMIB ZenPack so it now works for me on Zenoss 4.2.3. I have put a py2.7 version on http://community.zenoss.org/docs/DOC-11311 .
As always with unknown ZenPacks, if you have a VM I would take a snapshot first and then try installing the new version of the ZenPack.
Cheers,
Jane