Conflict with Custome Background Changer

Recently up-dated from version 1.6.7 to 1.7.4 after having problems with broken page header and footer.

I solved that problem only to discover that the newer version of the them is not compatible with an old pulgin I use – Custom Background Changer.

ISSUE: normally the background could scale to fill the screen (for larger workstations), but not the image is fixed.

The plugin hasn’t been updated for a couple of years but was compatible with the older version of the theme.

Any suggestions of how to deal with this and keep the theme up-to-date? Otherwise I shall revert to the older version of the theme.

The page I need help with: [log in to see the link]