I've recently added some tracking events for Google Analytics. One of the strings I tack onto the event is the "document.referrer" string. I'm finding that my events frequently show referrer paths, but analytic's default tracking behavior frequently reports "(not set)" when my events report very long referral strings. I've gone so far as to create an event that is posted using gaq for every _trackPageview initiated, and again GA reports (not set) when the event reports a very long referral string. Many other Analytics data points associated with the _trackPageview "push" are accurate and complete, just the referral path seems incorrect in many cases, again in some it's OK.