This is a fresh install (yesterday) and the latest versions of WP and NextGen Gallery.
There are several issues, ALL in the admin and ALL links on the frontside.
e.g. the save button in Other Options, just goes to the domain.com, as the other saves also.
In IE I can see the link and just show http://domain.com as the Save button link.
e.g. images pagination, when in a gallery (50 per page) goes to the domain.com
e.g. sorting by title, date or any other of posts, pages, galleries just goes to the domain.com
As soon as I de-activate NextGen all these problems are solved in the admin.
I have tried to de-activate ALL other plugins, except NextGen, but the errors remain, therefore it MUST be a NextGen error.
With NextGen de-activated the title sort of post goes to:
http://domain.com/wp/wp-admin/edit.php?orderby=title&order=asc which is correct.
NextGen activated it goes to:
On the frontside all links go to the index.php with NextGen on and when de-activated all links work great on the frontside.
I like NextGen very much and hope I don't need to delete it and look for an other Gallery option