[xwiki-users] border disappears

Dear All I want to have a 4px border between the left hand column and the rest of the wiki. I have added it to screenlayout.css to .layoutsubsection {border-left: 4px solid black;} (This may not be the right place of course, but it seemed to work.....) In FF and opera this is fine. HOwever in IE7 I get some odd behaviour. Parts of the line disappear as you scroll down the page. You can see a screenshot of this at http://www.ee-web.co.uk/caastIE7.jpg What is really odd is that I think it is something to do with the html/css that i have added to this page since on other long pages the line is always continious as i want it. I haven't posted the code because it would make the email too long. But I would be really grateful if someone could just look at the code and tell me if it looks ok because I can't see what's wrong. Its my first time skinning a wiki. I would prefer to use html than macros. thanks Edward