The 2 pages you give examples for working have a difference compared to those which don't work. In the code for the working pages (getstarted and download) there is no tracking for HitTail or Crazy Egg.

My guess is one of these is confusing Google Analytics.

The 2 pages you give examples for working have a difference compared to those which don't work. In the code for the working pages (getstarted and download) there is no tracking for HitTail or Crazy Egg (and both HitTail and Crazy Egg are javascript tags to third party sites).

My guess is one of these javascript code blocks is confusing Google Analytics.