Kannel(1.4.0) is not creating get-url for MO message

Hi All,
I am using Kannel gw 1.4.0 for both push & pull. push is working fine.
The problem arise when A MO message is coming from smsc to the kannel GW
(Using SMPP ).

ISSUE -
When a MO message is coming from smsc to gw, gw is creating a url (taking
get-url from config) of our short code platform.
It's working fine, but after a random number of messages gw is not able to
create url (get-url).

Inorder to make gw workig properly I am strating it again, now for some hour
it works fine and after some timethe same problem continues.

Waiting for reply.