Most of the features from the NextGen Gallery plugin are working well with WPML, however, there is a known issue with paginated galleries. The purpose of this errata is to make you aware of the problem and let you know that we are working on resolving it.
If you create a gallery with the NextGen Gallery plugin and you make it paged, pagination will not work for galleries in secondary languages. If a user clicks a link to a gallery subpage, he will be redirected to the gallery in the main language instead.
Galleries without pagination are working without any known problems, so if this is acceptable as a workaround, for now, please consider creating galleries without pagination.
When this issue is fixed, in cooperation with NextGen Gallery’s authors, we will release a new version of our plugins accordingly.