site ok in Firefox, not in IE : float problem??

I am working on a site at http://v4.beta.beerbergman.com/fr/
In firefox it shows up like it should be but in IE the textblock shows up 'under' the menu in spite of the float:left setting for the menu-layer.
I've made several sites with the same system but I cannot seem to find out what I did wrong this time:-)
The stylesheets are on
http://v4.beta.beerbergman.com/-http/-style/general.css and
http://v4.beta.beerbergman.com/-http/-style/menu.css

Any help would be greatly appreciated. It's been 3 days....

I think, the reason you have the problem is because IE does not follow the CSS spec whereas FF does. Specifically, in your case, IE uses the "width" element incorrectly.

IE includes the padding and border width in the determination of box "width". FF does not.

Remove your padding and borders from layout boxes and FF and IE will act identically with respect to box widths. I have how-tos on my website that give more detail if you are interested.

Your content box is moving down because:

(its width (according to IE) + the nav width ) > the width of your enclosing parent.

I think you can also get rid of some of your IE kludges too. I've never used one myself. I just work within the spec using code that works identically for both browsers.

The only problem with what I told you is I do not know how these things act on legacy browsers. But nobody has complained yet either.

You can still use borders and padding, but only if they are not pushing the limits of the width of your enclosing parent box. You can also put borders inside layout boxes to achieve the same goal.