TN Deployment issue

Hi All

We are facing issues when we migrate TN processing rules through deployer

Our env : IS 6.5 , deployer 6.5.1

We are creating delpoyer builds from our dev env , storing it in config tool (CVS) and migrating these builds to target env (STG/ PRD) through deployer
Problem : as soon as we migrate processing rule , all existing processing rules in target env are getting wiped out and only new one getting created

Pls let me know if anyone has faced similar problem …any suggestion

Regards
Deepak