I have SBS2011 Std and 2008R2 Std installed on seperate servers. I have detailed the setup in this (http://www.experts-exchange.com/Software/System_Utilities/Remote_Access/Q_26897476.html
I solved my problem (maybe???) when I discovered that the Security Groups that couldn't log on were not members of the RDS Server's LOCAL
Remote Desktop Users group. This is rather than (what I expected) the domain Remote Desktop Users group.
Anyway, as detailed in the thread above, I have three Security Groups that I want to use RDS and to have different restrictions apply. The groups are named RDS Users, StaffRDS and Students. When I add these groups to the LOCAL Remote Desktop Users group on the RDS Server they can all log on remotely and everything works as it should. However, after 20 - 30 minutes the StaffRDS and Student groups cannot logon BUT the RDS Users group can. When I check the LOCAL group on the RDS Server the group RDS Users are still there but the other two groups have disappeared.
Can anyone please tell/suggest me what is going on here???
PS. I cannot add the Domain Remote Desktop Users group to the local group on the RDS Server.