First, I unloaded the small sqlite database, only the table ' MediaTable' has rows of all the picture files (around 1323) and I checked with a script: all the pictures are existing.

Second, I tried to attach strace to the starting proc gallery-app, which is a bit tricky, because it is launched from the Unity desktop. But I managed it and, surprise surprise, the problem is that is spending nearly all time with nothing else at these syscalls:

stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2619, ...}) = 0
stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2619, ...}) = 0
stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2619, ...}) = 0
...
nearly 200.000 times:

root@ubuntu-phablet:/home/phablet# grep /etc/local gallery.tr | wc -l
192097

Any ideas what the hell it is doing with /etc/localtime?

Matthias