Problem with Dreamweaver 8

I'm running Dreamweaver 8 on my MacBook, with the latest OS X update (but this did happen before the update as well). When I try to edit a long page, the text will just dissapear in design view at a random point in the page. Go to http://www.seinman.net and click on the big middle finger to see the exact page i'm talking about, it wouldn't let me put the URL here because it contains a profanity. In this example, you can see that all the code is there, and it shows up just fine in all web browsers, but Dreamweaver won't display the design correctly. Above the random point, everything is fine (and easily editable), below the point all you see is the background of the page. Any ideas on how to fix this?