NFS? TeamSite? Solaris?

System

Can anyone explain this. If I create a new workarea, and a user who does not have permission on that workarea performs an ls that uses properties other than file name on the parent (WORKAREA) directory, sometimes it works and sometimes it doesn't (ls with no parameters always works). I haven't determined the exact conditions where it works and doesn't - it seems a little random. Is this an NFS issue, a TeamSite issue or something else? The output looks something like this (executed by the same user moments apart).

sncdevgms1:/default/main/branch/WORKAREA>ls -ltr
drwxrwx--- 4 user group 512 Sep 15 11:38 wa1
drwxrwx--- 2 root nobody 512 Sep 17 17:51 foo

sncdevgms1:/default/main/branch/WORKAREA>ls -ltr
./foo: Permission denied
drwxrwx--- 4 user group 512 Sep 15 11:38 wa1