I know I complained three times and only got the standard replies such as, calibrate, reset, auto-locate, etc. The rep I spoke to each time didn't really seem very knowledgeable. finally I just told them to send me a new unit which they did. I received it yesterday with software version 2.5 (not the 2.5.1 beta) and GPS 2.6. I will watch it closely to see if the problem still exists. My guess is it will.
This unit is going to end up going back as well though as the fit for the battery cover is really awful. I even tried the back from the first Colorado and still got the same fit issue so it is not the cover piece that is the problem it is the unit itself. The back slides off extremely easy, not that nice tight fit I was used to and the gap near the top is a joke, water will pour into this one.
Actually I believe you'll find that waterproof seal is inside the unit and not where the gap is shown in your picture. I also was unhappy about this gap, but realised it is not the seal. Why they didn't sort the tolerance out here and add another seal, who knows. On the accuracy side, my unit seems okay, and I've only had problems when under heavy tree cover. Why the track jumps by 100 odd meters in a second I have no idea (software logic could prevent that, based on previous averages, etc.). Hopefully improvement will continue to come from Garmin. More concerned if these are fixed by hardware revisions - where would that leave those of use with current units?