Does anyone have any ideas about the following?

Our setup is OES2SP1 server with the latest updates applied as of today and Mac OS 10.5.8. The user accounts have full permission in the directories in question and all operations perform fine via NCP and CIFS on windows but when using a mac it looks like any rename operation completes but all files in the directory where the file was renamed on the mac vanish. The files are all still on the server and available but the mac no longer has access to them. When I disconnect and reconnect all the files are there again until I rename something else. It even looks like I can copy files into the folder and create new directories but if I rename it same result.

So far I tried turning off unicode but that did not seem to help. The only message in the log that looks like may refer to the problem is below but sometimes the message does not come up when I reproduce the problem so it may just be a coincidence.

CIFS[9083]: ERROR: CODIR: GetEntryFromDirCache returned error
I know some people will say why not use AFP and I probably could I just thought it would be easier to support just one non-NCP protocol and not have to worry about the stuff like cache coherency (though we probability will never run into issues like that)