error in gpx exporting

[fraform@…]

What steps will reproduce the problem?

1. load an osm file with "ele" tag
2. export to gpx
3. draw elevation profile

What is the expected result?

a gpx file with "ele" tag as child tag of "trkpt" (​http://wiki.openstreetmap.org/wiki/GPX#Example)

What happens instead?

a gpx file without "ele" tag as child tag of "trkpt"

<?xml version='1.0' encoding='UTF-8'?>
<gpx version="1.1" creator="JOSM GPX export" xmlns="http://www.topografix.com/GPX/1/1"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">
  <metadata>
    <bounds minlat="39.1139762" minlon="16.7258345" maxlat="39.1253181" maxlon="16.7770594"/>
  </metadata>
  <wpt lat="39.11558" lon="16.7770594">
    <ele>552.7584582400307</ele>
  </wpt>
  <wpt lat="39.1156043" lon="16.7769849">
    <ele>553.9859917984311</ele>
  </wpt>

....

  <trk>
    <trkseg>
      <trkpt lat="39.1253181" lon="16.7258345"/>
      <trkpt lat="39.1249844" lon="16.7258595"/>

...

      <trkpt lat="39.1156043" lon="16.7769849"/>
      <trkpt lat="39.11558" lon="16.7770594"/>
    </trkseg>
  </trk>
</gpx>

Please provide any additional information below. Attach a screenshot if possible.

Revision: 8145
Repository Root: http://josm.openstreetmap.de/svn
Relative URL: ^/trunk
Last Changed Author: Klumbumbus
Last Changed Date: 2015-03-16 23:07:23 +0100 (Mon, 16 Mar 2015)
Build-Date: 2015-03-18 02:31:09
URL: http://josm.openstreetmap.de/svn/trunk
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last Changed Rev: 8145

Identification: JOSM/1.5 (8145 it) Linux Debian GNU/Linux 7.8 (wheezy)
Memory Usage: 307 MB / 786 MB (67 MB allocated, but free)
Java version: 1.8.0_40, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM

Plugins:
- ElevationProfile (30892)
- geotools (31000)
- jts (31002)
- opendata (31050)
- utilsplugin2 (31040)