sorry, but late to game… what is status? in post #10, you seem to indicate all is well but check boxes not appearing? is that what we are still talking about?
have you by chance disabled them in sp-config.php?
its late, please forgive me if off base… 
Hi, better late than never 
Yes, in post 10 I conclude that the cfoms plugin was the reason for the pictures not working.
Now were talking about BG images in the CSS not showing up. (checkboxes, radio buttons, close button etc…) Post #11 seems to be a good explenation of the current problem.
I have not altered anything in sp-config.php
The problem is present in all SP Themes and overlays, even with all WP plugins disabled.
Have you tried with the combined CSS option turned off? That should make it more of a relative url in the CSS.
The option is in Forum Admin > Options – Global Settings
And that is what’s so magic about you guys
Working like it should.
Thank you so much, all three of you.