White annoying square when scrolling

This never happened before and it is a brand-new installation.
When I scroll down, this white box appears just over the Footer
If it is a new feature then I don't want it.
Edit: Oh! It's the page background color! So I could do a "repeat y", but that looks pretty ugly. Maybe set the background color to a dark green? *sigh*.
Edit-edit: FIXED. The correct setting is FIXED!!! HA! Feels good to put my woman in her place.... "Don't move woman! Stay fixed in your place!"
Oh yeah!