are they added as serverpackages in ini ??
Example

cut/paste from UT ini
[Engine.GameEngine]
CacheSizeMegs=4
UseSound=True
ServerActors=IpDrv.UdpBeacon
ServerActors=IpServer.UdpServerQuery
ServerActors=IpServer.UdpServerUplink MasterServerAddress=unreal.epicgames.com MasterServerPort=27900
ServerActors=IpServer.UdpServerUplink MasterServerAddress=master0.gamespy.com MasterServerPort=27900
ServerActors=IpServer.UdpServerUplink MasterServerAddress=master.mplayer.com MasterServerPort=27900
ServerActors=UWeb.WebServer
ServerPackages=SoldierSkins
ServerPackages=CommandoSkins
ServerPackages=FCommandoSkins
ServerPackages=SGirlSkins
ServerPackages=BossSkins
ServerPackages=Botpack
(you must add skins here)
A good resource:
http://www.planetunreal.com/TheAdminPage/