Translating global navigation is not a feature of PointFire 1.1, the current version, but it will be a feature of PointFire 2.0 coming out soon.
In the meantime, the PointFire User Guide explains, in the section entitled "Translations of UI Elements", an alternate method for how to provide translations for global navigation and other UI elements. Essentially you can export the strings in resx format, edit the file, then import the file again. Version 2.0 will do this nearly automatically.
Unfortunately, it is not as simple as it sounds. SharePoint will NOT include navigation nodes in the list of exported strings UNLESS someone has already attempted to translate them using the user interface. SharePoint will include site names, list names, column names, and custom actions automatically, but NOT navigation nodes. Even if the navigation item is the name of a list and you have translated the name of the list, the string in the navigation will remain in the original language.
In order to make the navigation node appear as an item in the exported translations, you must:
- Change your user interface language to a different language
- While in that language, click on "Edit links", or the equivalent in that language
- Click on the desired link
- Change the text. The text must be different. Repeat 3&4 for all the links
- Click on Save
- Go to Site Settings -> Export Translations again and follow instructions
This time the navigation node will be included. Even if you have 5 languages, you only need to do this in one language other than the site language and SharePoint will export/import the string for all the languages. Don't try to just add the navigation node to the .resx file, it won't work.