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