Can’t change permissions – “The parameter is incorrect”

I too have run into this issue. Support recommended I upgrade to .17 (Not .19) to fix an Iscsi connection dropping issue. After the upgrade, I can no longer create users in AD and point their home folder to the "Users" share I created on the NAS. I get the "Parameter Incorrect" error. Also, when I try to add users, or change permissions on other existing shares (Departmental drives), I get the Parameter Incorrect error! So far, no one has reported any issues accessing existing shares since the "upgrade" (to use the term loosely). I am just dead in the water when it comes to moving forward. However, I have been able to create new shares, and set permissions which allowed me to point user's home folders to this new share in AD. I don't plan on using this though, because I have no intention of adding more users to what I consider a broken box. This really worries me because I have about 100 user's home folders, a bunch of departmental folders, and an Iscsi connection to a Symantec Enterprise Vault email archive on this box! If this goes down, I'm screwed! Support seems to be taking stabs in the dark telling me to do some of the workarounds that are posted here. Considering the mixed results, I'm sitting tight until an actual solution is reached. Any word as to what's happening with this?
I have a Windows 2003 AD environment with XP workststions.