Dear OP,
Please Clarify my doubt, are you creating a condition record for both PR00 and ZMRP for a Single Material ( I mean Line Item) and Trying to Test it?. If so "DO NOT" test by creating single condition record for A MATERIAL instead. Have two material and create condition record one for ZMRP and other for PR00. This should work.
More Over the Scenario which you are trying to explain me does not seems to be business there in Business Scenario
Please correct me if my understanding is wrong :
Regards
MShetty