Hi Piet. This is what I did:
Firstly you'll have to look for the album-compact.php file (wp-content/plugins/nextgen-gallery/view/) and make a copy for alternative languages: in my case the main language is Spanish and my alternative language is English. So, i created a file called album-compact-eng.php
Then, on line 25 I just added some characters (&lang=en) at the end of the link to the gallery:
<a class="Link" href="<?php echo $gallery->pagelink ?>&lang=en">
This patches the links to galleries in alternative language, that was my main problem.
Then, I did the following:
1. with NextGen I created galleries, albums and uploaded images. Make sure of creating a page for each galery, this is just by pressing "Add page" button in Manage Gallery. This will create a page in the default language (as you might have set up firstly with WPML plugin). NGG automatically creates a page with the [nggalery id=x] code on it.
2. Go to Album and create an album with all the galleries you want.
3. Go to Pages and open the galleries pages and add the translation. You will have to copy the same [nggallery] code.
4. Add a page or post to show your album in the default language and add the [album id=y template=compact]
5. Add a translation to this page and in the content, just add [album id=y template=compact-eng]
That worked for me. When finished, I'll post the URL to the website so you can see it.
Hope this be usefull. Feel free to ask if something's not so clear.
ivank123