Ye, it seems that the UDKmenu.ini got edit from the last Update (Beta 5)
So get the Map again to the Map List for Skirmish you have to follow the Instructions, in the Download Folder i can find them.
GameplayMaps=(Filename="CNC-Eyes",Description="Eyes",Size="Large",Style="Symmetrical",RecommendedPlayers="12",AirVehicles="Enabled" TechBuildings="1",BaseDefences="Basic", MapImage="img://RenXFrontEnd.MapImage.___map-pic-cnc-canyon")
Copy that to the other Maps in the UDKmenu.ini that should solved the Problem.