White space at bottom of page

I'm having all sorts of issues but one is fully stumping me and continues to drive me mad. I'm hoping you all will have some suggestions.

My Zen Cart pages are being cut off at the bottom of each page. It displays white space on the bottom and cuts off the design I have in place.

HERES THE LINK...

https://www.openheartthreads.com/products

Notice how the page is cut off on the bottom. When I view full screen in my browser a large white space appears where it cuts it off.

I've disabled the footer and banners but that doesn't do it.

I'm on a deadline for this one so your help would be SO very appreciated.

Thanks in advance!
Robert

I figured it out!

I changed the #mainWrapper in the stylesheet to a height of 768px.

Does that seem prudent? Are there potential issues with that?

i don't think is good idea to restrict your websites Height . as you may add more content to the page, such as additional sideboxes , they require more height , otherwise , they may overlap ..

I think , problem might be with your background. i was not able to figure it out but , replace your background with solid color and see if that fix the problem .
on my monitor , your background is repeating horizontally.

And, your site is really messed up in Firefox.