Some elements always parse to nil

[Amidee89]

I'm making a template gpx to test all parsing from coreGPX, but I can't get track number not to parse into nil.

I'm putting the file here, it's WIP and is still missing routes, but can be useful for future tests.
testgpx.gpx.zip

[Amidee89]

same goes for ageofdgpsdata, apparently.
Updated example gpx here @vincentneo
testgpx.gpx.zip