SBS 2011 and SBS 2003

Hi,

I have inherited a nightmare scenario with an issue with shares.

We have an SBS 2011 server with a 2003 SBS server running as a virtual machine (Not Hyper-V). I have shares on the SBS 2003 machine that current users can gain access to. If I add a new user to any groups (including domain admin) I can't gain access to the share. I am sure the SBS 2003 is still a DC in the domain but replication has been disabled.

Any help with how I can get new users to connect to the share or the reason this is happening would be great.

Thanks.