Irule redirect looping

Thank you so much ... finally figured it out esp after your reponse. The issue was

test.mydomain.com - new LB

we have been migrating from a old f5 LB to new f5 LBs and a much larger version of this irule was sitting on the old LB ... so once the rule passed the first time on the new LB (irule) it would then be handed over to the old LB where it would run through the irule there..where instead of "starts_with" the old version had "contains". thus causing the loop. Have removed this section of the code from the old irule... and all works good now...