NextGen gallery Image size problem

I am have just made my NextGen gallery images open in my website like normal instead of opening in pop up windows like it usually does.

But my problem is that the images are now huge and not resized to 800X600 like it says it is in the settings page.

My aim is to get the images opening up to a decent size on my websites theme with and to put paypal buttons and information underneath them. I would be gratefull for any help!

My website http://www.akwete.co.uk.