GTK applications behave weird if locale is set to anything other than "C"

[Rolf Schäuble]

Hello,

I've come across a pretty weird problem:

At first, I noticed that the "open file" dialog of Gimp didn't show  
files and directories in alphabetical order (I clicked on the column  
header a few times to make sure that the dialog actually try to sort  
by file name).
I also noticed that two menus were missing (skript-fu and python-fu).
As that time, my locale was set to de_DE.UTF-8.

Then I changed LANG/LC_ALL to C. Suddenly the order of files in the  
"open file" dialog was correct, and Gimp displayed the two missing  
menus. It seems that of all locales, only C works. de_DE (without the  
UTF-8 part) didn't work, and neither did en_US or en_GB.

I could find the same issue in gnucash. Only with the C locale did  
the "open file" dialog display files in the correct order.

My MacPorts packages are quite up-to-date (I did a full upgrade  
yesterday after finding the problem, but upgrading didn't change  
anything).

Does anyone have some ideas, or hints of how I could continue  
narrowing this down?

Thanks a lot
Rolf