I am running into an issue where if I click on the pagination for a gallery that is on a category page, it adds categories after the post name on the next page. This then results in a 404.
However if I am in a post and click the pagination, it just adds the nextgen URL to the next image appropriately without the category information. This results in a successful linkage.
For example, if I am here http://sitename.com/%category%/, and this page is a list of posts under that category; then click the next page under one of many galleries on that page, the URL created on the next page is http://sitename.com/%postname%/%category%/%NextGENURL%/ when it should route to http://sitename.com/%postname%/%NextGENURL%/ because that is the only thing that works. I tried to see if it was caused by WordPress permalink structure, so I updated the structure from http://sitename.com/%postname%/ to http://sitename.com/%category%/%postname%/ and I end up with the result of http://sitename.com/%category%/%postname%/%category%/%NextGENURL%/. This makes me think that for some reason, NextGen is adding the extra category URL for some unexplained reason.
I hope I explained this well and looking forward to your response and assistance.