Issue with DIV width in IE6

This may be the famous IE scrollbar bug, but it seems slightly
different and I thought it was fixed in IE6.

I have a non-nested DIV (id=content) with the following CSS entry:

#content {
position:absolute;
background:#dee;
margin-right:20px;
margin-left:225px;
margin-bottom:20px;
border:1px solid #dee;
}

Basically the aim is to offset this 225 pixels from the left to make
way for a left nav bar. However, I end up with what appears to be an
approximate 225px margin to the right of the div, causing text to run
off the right of the screen. There are no such problems in Mozilla.
I've tried the workarounds seen on the web, but none seems to work
which makes me suspect this isn't the bug that I've been reading
about.

You can see the problem at:

http://caterhamacademy.dnsalias.com/CaterhamAcademy/

Could anyone either propose a solution or confirm that this is a bug
in IE6?

Regards,

Charles