Open Home Background not scrolling

I have had open home (full version) for a few weeks now and I'm very pleased with it so far. The last couple of days I have been rearranging my folders and widgets and some of the open home settings.

I also changed my background but when I chose the picture I wanted I only got the option of cropping in portrait. Now the background doesn't move from side to side when I change screens.

I am assuming it's a setting I changed when I was playing around but I can't find any way of changing it back to the original landscape background that moves from side to side.

I have a G1 with 1.6 update.

I hope that makes sense, please help???