@Joseph,
I totally agree with your statement: "Actually I believe it is almost impossible to translate correctly the language strings if you do not have a running instance of Moodle on your desktop, where you can actually see and understand the scope and semantic value of the strings you are about to translate."
Would you be so kind as to include this very wise advise for translators in the Moodle Docs for translation, at http://docs.moodle.org/25/en/Translation ?
Thanks,
Germán Valero