There's been a lot of discussion on the Apple forums about Server Monitor connecting from a Tiger client machine to Leopard Server machines, however, I'm actually having the inverse of this problem. Specifically, I've got an Intel XServe running 10.5.3 that's the OD master for the domain, and an ancient (generation 1) G4 XServe running the 10-client release of Tiger Server (10.4.11) getting its OD information from the Intel XServe. It was previously running Panther Server 10.3.9 as the domain master. When the G4 XServe was running Panther, Leopard's Server Monitor on the Intel XServe could see it fine, but now that it's running Tiger Server, I get "unable to connect" errors. Any ideas what's going on here?