Let me preface this by saying that I am not an expert in this but it
sounds like something that happened to us also when we switched our old
machines to G4s also (same error 519). I tried several things but my
first thought though is because you said it worked through AppleTalk,
you might have to
We have been having ongoing problem with G4 machines (Apple machines,
not upgrade cards) dropping out of backups with 519 errors and
leaving OT not working on the client machine (we can restore it with
a sleep/wake as well as a restart).
We have not yet tried changing the protocol to
