On my site www.bibelaabner.dk I use both CommunityBuilder and the JoomlaQuiz Deluxe component. I have quizzes on many pages on my website.
But: When a user logs in using Internet Explorer (and this is a problem ONLY in Internet Explorer (and Safari)) all the pages containing a quiz align to the left. The pages simply remove the modules I have put in the left column, including a CommunityBuilder module.

So either this has to do with the JoomlaQuiz Deluxe component and/or the CommunityBuilder component.

The W3C Validator says there is a problem with something in the CommunityBuilder. It says 'comprofiler' contains an invisible character in the source immediately before the start of the form tag: <form action="action="www.bibelaabner.dk/index.php/component/comprofiler/login"

Could it be the CB thing or could it be the Quiz thing that causes the pages to left align and remove all modules in the left column?