I have an OES11 (fully updated) server that runs cifs next to the normal NCP so a few windows servers can get at the files on the nss volumes.
A few weeks ago our xenapp servers suddenly started giving errors accessing a volume via an unc path, it appears for some reason the windows servers started favouring cifs over ncp when trying to access a volume.

I'm not entirely sure why the cifs is failing (it should allow access with the MS credentials), when restarting the cifs service access to the volume is restored for a while.
Mapping the volume works fine too, it's just when you try to access it over unc.
I already moved the netware provider to the top of the network providers but that didn't make a difference.

Anyone have any ideas as to what might be going on ?