Sure! Looking at the discussion you commented on, my first suggestion is to not upload it as a side image. Ning uses vertical column navigations by default, so everything is usually set up for top center. If you side image, it will always orient that background to the side, and the actual page module center, and that would explain the browser variances you've mentioned.
Unfortunately, I'm not a code ninja! I think since you posted your question at the tail end of another person's thread it went unanswered. It's easy for a cold thread to fall pages back in the forums. If my suggestion doesn't help, I'd repost your own question perhaps with a link referencing this old thread.
You do a good job with the value proposition on your proprietary site. I could not get into the services link though. FYI, your profile answer listing your Ning is private. I'd be happy to look into your network if you want to share it.