Not sure if this will help with a page, but it seems to be related: Delete WordPress Category – Numbered Slug Fix using PHPmyAdmin
Okay, I was too quick to post that question. I found the CSS that tr33mrn was talking about. You have to edit the CSS of the plugin itself, not the theme CSS (duh!). Go to plugins > nextgen-gallery > css and do a find for “clear:both;” remove those styles and the problem should be fixed.
I am having a similar problem where the NextGEN gallery in the current post shows up just below the vertical position of the sidebar. In all the other posts, the NextGEN Gallery is in the correct place relative to the text, but the first post for some reason has a problem. Check it out: http://swanklighting.com/blog/blog/
Thanks for any suggestions.