White space…

Hello everybody,
My problem is the following:
When I put the NextGen uploader widget in my sidebar (which is on the left of the page), the body of my page is moved below the sidebar… when you connect to my site, you just see a big white space with the side bar on the left, and you have to scroll down to see the content at the bottom of the page.
The NextGen uploader widget is the only widget that causes this problem. It occurs only with internet explorer 6… as usual…

Could you please tell me what could I do to fix it? (My stats show me that 50% of the visitors are under IE6 )
My WordPress version  is 2.8.5
I use NextGEN Gallery Version 1.4.3 and NextGEN Public Uploader Version 1.5

Thank you!
Sophie