Contact Form 7–Text degrades when user scrolls

We are using Contact Form 7 version 1.7.7.1 on our website (visioncredit.org).

Everything works properly and it looks as we intended (in the right sidebar). We are having a problem however with the appearance of the text labels in the form. When a user of IE6 or IE7 scrolls down and then back up, the text tends to appear corrupted and hard to read. When you allow the mouse to pass over the javascript drop down menus, the text snaps back to the correct appearance. It is a weird phenomenon that does not occur in firefox.

Is there anything that we can do, or is this something we have to live with? We chose this plugin because the others were harder to fit into a sidebar.