Hi,
I've set up a fresh zenphoto install and it seems that image are not automatically rotated based on EXIF data (photo are well displayed on Windows client for instance).
If I rotate from zenphoto, the rotation works well (the first photo have been rotated through zenphoto), it seems it's just the automatic rotation that doesn't work.
There is no error during displaying image in apache log neither in zenphoto debug one.
Did I miss something ?

Here is a link to the zenphoto gallery:
The https://photos.martin.lc:8080/index.php?album=2015.01.23%20Bureau%20De%20Claire%2C%20Pathe

There is a bug in 1.4.7 and earlier. Please try the support build (you may need to rotate existing images manually though). Testing this helps us to be ensure the bug is fixed.

Just downloaded and installed support, clear cache and refresh, and it seems it's ok now, thanks a lot.
Could I stay on this support build version, or is it only for debugging purpose ?

You can stay on the support build version.

Ok, thanks a lot for your help

Works for me too with the latest support build version.
thanks