I noticed that the LAST page in my checkout funnel (the Invoice page) has several hits AS A LANDING PAGE in google anayltics, despite the fact that you can ONLY get to it by going through the checkout process (which means viewing at least three pages before it).
I wonder if PayPal might be messing that up? When a customer pays by paypal, they are taken to their paypal account page, pay there, and then are redirected by PayPal to the Invoice page of my site.
Does that sound like the cause? Or is it a bigger problem than that?
I remember an issue about it, basically I had to do a setReferrerOverride to record the right info by registering a session when the customer was landed on the site's pages. When he got back from the payment processor I would update the referrer with the one I was previously tracking.