Concourse G at KORD is exclusively for American Eagle aircraft. If you have American Eagle planes at KORD, open up the aircraft.cfg files and make sure under the parking codes segment of the flightsim.xx file it says AALX. I think the AFCAD for the FSDreamTeam ORD package sees the parking codes for American Eagle as AALX. So make sure you have that code.
If you don't know, American Eagle operates the Embraer 135/140/145, and Canadair CRJ-700 out of ORD
hope this helps