While still not appearing on the NetWorker compatibility lists, it would certainly appear from testing that NetWorker 7.6 plays a whole lot nicer with Mac OS X 10.6 (Snow Leopard) better than its predecessors did.
Previously when Snow Leopard came out, I posted that NetWorker 7.5 was able to work with it, but did qualify that if you were backing up laptops or other hosts that periodically changed location, NetWorker would get itself into a sufficient knot that it would become necessary to reinstall and/or reboot in order to get a successful backup. (In actual fact, it was rare that a reboot would be sufficient.) Fixed-point machines – e.g., servers and desktops – typically did not experience this problem.
It would seem that 7.6 handles location changes considerably better.
If you’re experiencing intermittent problems with NetWorker 7.5 not wanting to work properly on Mac OS X 10.6 hosts, I’d suggest upgrading to NetWorker 7.6 as a test to see whether that resolves your problems.
The usual qualifiers remain – read the release notes before doing an upgrade.