Comment 10 for bug 966734

I found a discussion from 2008 on the net which seems to indicate that this is by design and won't get changed:

http://thread.gmane.org/gmane.linux.nfsv4/7103/focus=7105

Sad, but probably there is nothing that can be done about this (aside from using Kerberos, syncing IDs, or switching to Samba).