If I can just get your opinion on this one too please?
I can only get the background colour to work with theme designer mode turned off on IE8 and IE9 , not firefox or chromium based browsers.
Oddly with theme designer mode on, all browsers show the background colour and it also works temporarily when I use the preview button on the theme settings page.
I've set the background using theme settings and in the CSS at the same time, purged my caches, validated my CSS, stuck !important on the end of the css rule (as suggested in another theme related post elsewhere by Mary) and installed 1.8.2.
I'm almost ready to let this one go as I'm only after #EEE and we are largely an IE8 monoculture in our college but I'm trying here as a last ditch attempt at a fix.