[Koha] languages lost after upgrading from 3.0 to 3.6

[Gerard Henry]

hello all,
i'm doing the upgrade. In 3.0, we have the languages:
en
fr-FR
de-DE
ed-ES
in opaclanguagesdisplay

but after the upgrade, opaclanguages display is empty, it is not 
possible to select languages.
The dirs are presents:
# ls -l /usr/local/koha/opac/htdocs/opac-tmpl/prog
total 28
drwxr-x--x 7 koha koha 4096 2009-11-26 18:40 de-DE
drwxr-x--x 8 koha koha 4096 2009-11-26 18:40 en
drwxr-x--x 8 koha koha 4096 2009-11-26 18:40 es-ES
drwxr-x--x 4 koha koha 4096 2012-06-27 10:39 famfamfam
drwxr-x--x 8 koha koha 4096 2009-11-26 18:40 fr-FR
drwxr-x--x 2 koha koha 4096 2012-06-27 10:39 images
drwxr-x--x 9 koha koha 4096 2012-06-27 10:34 itemtypeimg

what am i missing? anybody can help?

thanks in advance

gerard