Route & Climbing question

It should count all of the climbing and add it together.  NOT the ascent and descent added together.  If your route is rolling, the difference between your high elevation and low elevation may not be 308, but you could have ran 10, 30.8 foot hills to get 308.

If you are still suspect, backcheck with mapmytri or mapmyrun, or several other choices...

I'm a little suspect of all of them to be honest.  They are probably good with a 10%-15% error.  They all give numbers that fall within that range, including my Garmin 305.

For each point that you click on the map, we get an elevation value from the USGS via a web service.  That value is then checked against the previous point and if it's higher, the difference is added to the Climbing total. 

Understand that these aren't dead-on accurate elevation values we're working with. They're pretty good, but I wouldn't use them to build a house, if you know what I mean. They come (mostly) from a Space Shuttle mission in 2000 that used radar to generate a topographic model of the world. It's not perfect, but it's still quite good.