Have Nextgen AND Nextgen Pro
Just had this happen with me. Switched theme to one of the defaults. Corrected it and stayed corrected when activating the theme I was using.
I have this question too.
One thing to note regarding Themes. Another way to find out if a Theme is affecting something is to switch to a default WordPress theme like 2010 and see if that changes anything. In my case doing the ?rel=0 still did not work. Just sayin.
