FoldableLightBox document filter box in main listing view doesn't work with IE7 & IE8

2 issues:

• IE7/IE8 > when you click on the Filter link, to unfold the box, all the box disappear.
• IE7 only > when you fill the form and click on 'filter', the 'Clear Filter' link in not displayed (for IE7, the form id=cv_document_content_0_resetFilterForm is empty)