A: 

You might try add the clearfix class to your main block. It is defined here: http://www.webtoolkit.info/css-clearfix.html

It helps make browsers render the entire container, even when its contents are floated.

Alex Sexton
Thank you, that has helped me somewhat - however, having implemented that (assuming wrongly) that has now hidden my centre div?
Wayners247
perhaps it also needs to either be cleared or clearfixed as well?
Alex Sexton
As the div is using a class already to define its size and float, i have added the clearfix code to this class. Should that not work? Ive tried different variants of the clear and visibility commands but with no luck :(css code is:background-color:#39C; background-position:center; background-repeat:no-repeat; min-height:200px; width:70%; float:left; content: "."; display: block; height: 0; clear: both; visibility:hidden;
Wayners247
Thank you alex, i got it working thanks to your help :)
Wayners247
You should upvote answers that you think are helpful ;)
Alex Sexton
i am, but each time I do it says an error has occured :(
Wayners247
A: 

Thank you Alex, i managed to sort it by removing the height:200px command in the parent. Works fine in IE and firefox now :)

Thanks very much :)

Wayners247