Redstone repeaters are disabled, because they are main item, that you need for redstone clock, which we can call them lag devices, because redstone clock make a lot lag. I really dont know why you can puschare it... Maybe only donators can puschare it...
alkon7 you can purchase them and craft them; you just cant place them anywhere, the server won't let you do it. You can still make redstone clocks using redstone torches but that requires mre skill and causes a lot less lag then redstone repeaters (they are also slower too). Redstone clocks are practically useless in factions btw.