aha sorry everyone, after a few days with no reply here i removed the sidebar all together just to see what would happen. What happened is the background did not show at all. Right below the header started the footer! With my content overlayed over that.
I have put sidebar back into index.php file. I removed position: absolute; from the css and now my background does extend all the way down my content. However, it pushed my sidebar down quite a bit. I'll look at this, think i've seen that before. If i need help with that part i'll start a new post.
Thanks for the suggestion, not sure where i got that from, but removing it worked.