Google AdWords tracking issues with PayPal source?

Hello,

We’re running Google Adwords Campaign for one of our CodeCanyon item now. And we have I believe some tracking issues with PayPal source. Can someone please tell if PayPal source/session rewrites original AdWords source? If so is there any chance to track transaction from the original source not PayPal gateway? Please advise.

We don’t understand if PayPal session overwrites or duplicates original source (paid Google keyword)? Will it help if we add paypal.com to referral exclusion list on Google Analytics settings? We do want to track all paid sessions. But we have doubts if it works as it should. Thanks!

Best Regards,
Peter

Any fix for this?