Is there a difference in FPGA version or Board Type? Maybe a later firmware (that I haven't tried yet) shows the difference more explicitly.
One way to tell might be to check under configuration, and Radio tab, and check to see if the external gain/antenna gain option is fixed. This might also be reflected on the Status page on the Total Antenna gain line.
Thanks, the External Gain field on the Radio tab is indeed not editable on the 450d.
In 14.1.1, I don't see a line on the General Status page for Total Antenna Gain, but the Radio tab will help out for now.
I would also highly recommend updating software to R14.1.2 as soon as possible. Many fixes were put into the system for that release.