Office on Windows corrupting file rights on XSAN

MS Office running on my Windows Server 2003 Termserver is corrupting the Posix and ACL rights on my XSAN. This also happens with Office 2007 loaded on an XP Pro machine. We were using Office 2007 and I upgraded the Termserver to Office 2010. The problems got slightly worse.

I have a file named ray.xls for testing. If I give that file Domain Admin, Full Control rights I can open it as a Domain Admin but access is denied when I try and write. So I changed the Posix Group to Domain Admins and that allows me to save. The following screen shots show what is happening.

These are the rights before I open the file.

I open the file as jfuller (a domain admin), change one cell and then save and close the file. The rights change to this.

I open the file a second tme, make another change, save and close the file. This is the new rights.

From this point on, every time I save the spreadsheet it will add another ACL for John Fuller with Custom rights.

I have files with rights that have 30 or 40 ACL entries. What the heck is going on?

Any thoughts would be greatly appreciated.

John