DFS access denied

[it-hell]

Hi

We have DFS here which works well for xp client profiles/app data/my docs etc all using the netbios name of the domain.

Randomly though windows 7 will get an access denied error for accessing those shares. If you log out and back in it seems to work though.

DFS is 2008 r2 which is powered by a cluster 2008 fs. There are 2 dfs controllers as such and we dont use it for replication currently.

Can anyone think of any reasons it would be random like this?