Problem with FXO and E1 card

I have on my machine two cards. One is E1 and the other one is four port FXO. The problem is that i am unable to load its modules wcte11xp and wctdm respectively.
The problem is whenever i load modules like when i do "modprobe wcte11xp "
it gives an error ZAP_CHAN failed.
But when i do "modprobe wcte11xp " again it loads the module and everything starts working fine. I have also tried to load 4-port fxo card first but the problem is same.
Anybody having any idea what might be the cause?

are you loading zaptel first ?