internet explorer 7 - negative margin

hello,

I run a site with a zen subtheme and domain access.
In i.e. 7 the content of the site jumps to the right.

I resolved it in ie.css with a negative margin-left.
The problem is that the distance of the jump to right isn't the same for all the subdomains.
So if it looks ok for one subdomain, it doesn't for the other

http://www.sintleo.be
http://landscouts.sintleo.be
http://zeescouts.sintleo.be
http://muzikanten.sintleo.be
http://scoutsharmonie.sintleo.be

Does anybody has a solution?

Geert