[ubuntu-uk] nfs share not mounting after upgrade to Gutsy

[Mac]

After upgrading my old laptop from Feisty to Gutsy, the cifs shares for 
my network drive are mounting fine, but an nfs share to a folder on 
another computer on the network isn't.

When I 'sudo mount -a', I get

mount.nfs:  <serverIP>:/<sharefolder> failed, reason given by server: 
Permission denied

Given that it worked fine before the upgrade, I'm a bit at a loss.  Any 
ideas about what I need to do about this?

TIA

Mac