samba - Feb 2012 - Samba4 error? A global catalog (GC) cannot be contacted

Hi everyone

Every so often we get this error:
http://dl.dropbox.com/u/45150875/samba-list.png

The error disappears around 5 minutes after Admin has logged in, 
Meanwhile the user can logon and none of his group acls seem to be 
affected. Nothing unusual appears at d3 level either.

Anyone else? Slow network (It's supermarket-sourced-adsl-router wifi)?

Cheers,
Steve