Basecamp 4 : Information from the gpx- file not shown - Export Bug?

GPS Receicer: Montana 600
Track Mode: gpx
Basecamp Version 4.1.1.0 (Mac)
Tempe sensor

1.
I connected my receiver to my iMac and transferred the gpx file via Basecamp on my computer. In Basecamp itself all information (incl. temperature) will be shown.

2.
If I exported the track file via basecamp to Garmin connect (Send to Garmin connect) all additional information (i.e. tempe temperature recording) from the track will be lost

3.
Same behaviour if I exported the track via Basecamp to a gpx file and import this file manually into Garmin connect

4.
If I imported the track file directly (via Garmin Communicator) into Garmin Connect all informations are also available


What is the reason for this problem?

I would expect that the information about the tempe temperatur would not be lost if I'm using basecamp to organize my tracks


I made some additional investigations and I found out that there is a difference between the original gpx file on the device (Montana 600) and the Basecamp created exported gpx file :


Orignal gpx file

<trkpt lat="47.5102203246" lon="10.4085498769">
<ele>1288.78</ele>
<time>2013-03-27T08:43:47Z</time>
<extensions><gpxtpx:TrackPointExtension>
<gpxtpx:atemp>5.0</gpxtpx:atemp>
</gpxtpx:TrackPointExtension>
</extensions>
</trkpt>


Basecamp created gpx file (export):

<trkpt lat="47.510218312963843" lon="10.408548032864928">
<ele>1292.150000000000091</ele>
<time>2013-03-27T08:43:46Z</time>
<extensions>
<gpxx:TrackPointExtension>
<gpxx:Temperature>4.8</gpxx:Temperature>
</gpxx:TrackPointExtension>
</extensions>
</trkpt>


In the first (original) track file the TrackPointExtension has the format:

<gpxtpx:atemp>5.0</gpxtpx:atemp>

In the via Basecamp exported track file the format is as following:

<gpxx:Temperature>4.8</gpxx:Temperature>


For my opinion the second format is wrong; that would also explain why the temperatur is lost during export