Publishing Between Test and Production Environments

Hello:
PHPRunner 4.1 - Build 320
I'm having trouble using the FTP option to publish between our test and production environments.
It doesn't appear that the FTP publish option can keep track of what's changed between the build folders on the PC environment and the TWO different server environments (test and production, each with a separate FTP location defined on the Publish screen of PHP Runner).
When you switch the FTP location from Test to Production or from Production to Test, PHPRunner wants to upload ALL of the files rather than just what's changed between what's on the build folders on the PC and the target environment on the server (production or test).
Sure would appreciate any help with this!
Take Care... Mike.