How do you manage the arabic letters in the filenames?

Zenphoto should support everything that is withn UTF-8 spectrum and additionally of course your server must be setup to handle those characters in filenames and folders, too. The most servers I know don't even like german umlauts and the like.

tried everything too to get the right path in poedit, nothing, really nothing seems to work with my XP. I just can't update from source.

You probably did not enter the paths correctly. I supposed you read our theming tutorial?
Btw, what language are you trying to do? Please check if we have it or someone already working on it. You could also consider to join the translation google group (link is on our home page).