Error while copying a DTP

Hi Experts,

Its a simple yet confusing error to me. I copy a DTP which has some filters defined. I get an error saying both the DTPs can not have the same filter criteria - if its a Delta DTP. I say ok and try to change the filter values , interestingly the error still remains and my new DTP does not activate.

Please suggest how I can resolve this. I can not change the udpate method to "Full". It has to be a "Delta".

Appreciate your inputs,

thanks,

Shweta