QueueAddToProject method not working when general user hits the OnPublished event

Hi,

I have implemented the code on Onpublished even to update the custom field value, it was working fine when user logon as Admin previleages. But the a manager group member publish a plan the QueueAddToProject is giving error, saying that the "CICo checked out to otheruser " error.

i tried the impersonation but no luck, 

anyone can help me the situvation.

Thanks,

Sampat