As announced a month ago the UR2 update rollup for SCOM 2012 SP1 was released. One of the known issues of this update was that the gateway servers did not get their agent distribution folders updated. This was because there were no fixes for the bits of the gateway role itself. However of course the gateways do have the agentmanagement folder where the SCOM agents and their latest update can be found. This caused that folder to not be updated with the latest agent fixes. Simple workaround was to copy those newest files from an updated Management Server. Meanwhile Microsoft worked on a fix. A week ago Microsoft released through WSUS the UR2 update package for SCOM Gateway servers.
Good luck!
Bob Cornelissen