Connection With 1.7.9

Im using bukkit 1.7.9 on my hub and it works fine..
Im using bungee 1.7.9 it works fine to connect to hub.
I got 1.7.9 on factions and all the other servers but i cant connect to it via bungee i can connect with the ip thoe without connecting via bungee anyidea?

My client runs 1.7.2 it works to join the bungee when the bungee and bukkit is 1.7.9
but i cannot connect to my factions with 1.7.2 even when its the same version..

Please Help!
Thanks
~ Typhoon