Load GPS log into Aperture : why altitude is lost ?

Hello,

I was trying to get rid of the external programs I used to join GPS information to my photos by replacing them with the "places" function of Aperture.

After a bit of headscratching due to poor results, I found a Feb.2010 discussion where user mvanderbilt posted this :

--- quote ---

This is how I got Aperture 3 to assign correct locations to my photos using a GPX file (in my case, from a Garmin GPS device)

1) Import the GPX track data. You should see a purple line on the Places map.

2) Pick one of the photos in a project for which you know the location.

3) Drag that photo onto the correct spot -- Aperture helps you by showing the difference between the photo time and the GPX time. The clock on either of those devices may be off, or in the wrong timezone, and this first photo placement calibrates the timing for the rest

4) After you choose the location Aperture 3 will ask if you want to assign the locations of the other photos based on time. Click on "assign location" and the rest of the pictures will be placed relative to the location of the photo you located in step 3.

I wish the manual was more clear on this. It took a while to figure out what Aperture was doing, and my photos were often assigned to incorrect locations (but in retrospect, Aperture was doing what I told it to do).

-- unquote --

Well, tried with these instructions and apparently now everything is fine but........ where is the altitude data ?

I mean, my GPS logger duly write in its NMEA0183 file latitude, longitude AND altitude : why Aperture seems to recognize only latitude and longitude and NOT the altitude ?

I am sure of the logger because if I still use GPSPhotolinker all data are correctly transferred so, either I'm still doing something wrong or Aperture do not recognize the information.

Any hint / help ?

Many thanks to everybody & have a nice day.

Marco