Open Enterprise Server 2 Support Pack 3 October 2011 channel update
NSS Folder rights were set to Write, Create, Modify
After updating to the October 2011 channel update, users lost rights to folder
Adding Filescan rights, users were able to see the folder again, but they could also see everything in it
This issue has been fixed in the July 2012 patches for OES2 SP3 and in OES11 SP1.