What version of software are you running on 450m? Where are you located?
The pinout for the RJ-45 AUX port (on the 450m) to RJ-11 (on the UGPS) is highlighted here: http://community.cambiumnetworks.com/t5/PMP-FAQ/Cable-Diagram-for-450i-and-450m-to-UGPS/m-p/52198#M275
Yes, the 450m can provide the proper voltage to run the UGPS, but this must be selected in the software.