BuddyPress Business Theme-Header Image Positioning

Hi, I’m new to BuddyPress. On my new WordPress Site, under theme options (in the Business theme by WPMU Dev), I chose to upload a custom large header image. It doesn’t tell me what size to make it. So I made it at about the size it looked to be. I uploaded it and it appears to be about the right size but for some reason it did not center my header image in the space provided. Instead, it put it over to the right, hanging off the page about an inch with a about an inch margin on the left. And now you have scroll over an inch to see all of it. I have no idea how to fix that or why it did it that way. Can anyone tell me how to fix that? The url to view the page is http://whub25.webhostinghub.com/~united66/