In the below link search for the texts and from there you can change it.

http://www.site.com/admin/dev-tools/languages

PS: Replace site.com with your site.

THAT part I know... :)

What I need is to know the exact KEY for the invitation email body text...

If anyone knows, I appreciate it.

ok, I searched the db and found it. If you type in the search field for the language translation on dashboard for 

mail_template_admin_invite_user_content

You'll get both the text and the html versions to translate.

Hope it will help other users in the future, so I'll leave the topic here... :)

Thats it.. here you go.. Thats what I meant.. search and find :D

The point is that before I posted, I did try to search using the dashboard translation tool and got nowhere... I had to scan through the database to find it.

I know most people, specially in forums, are lazy enough to just ask before they try on their own, but when I ask for help, it's because I tried and failed. It's because I could really use some help... :)

The language translation section on the dashboard is a useful tool, but most part of the time it's really hard to find what you want. If the search is too vague, or if you don't type in the exact words in the original text, it won't return any results. And if I know exactly what I'm looking for, I don't need to search, right? :)