Linked mailboxes cant share mailboxes

[James Kerr]

Having some trouble with this. Here is my scenario, I have two domains in 
separate forests, domain1 and domain2, there is a two way trust between 
them. On domain1 we have an Exchange 2007 server. The users in domain2 are 
setup with linked mailboxes. The problem I'm having is that users in domain2 
can't share for example, their calenders, with other users in domain2. 
Anyone have any idea how to do that?

James