CSS layout issues with IE6

I have my page, located here, looking pretty much how I want it to in Mozilla and Opera, but there are some problems in IE6. The main content block's white background keeps breaking up in places. This sometimes goes away with a reload but if you highlight the text then the background underneath the highlighted text disappears again.

Another problem is that the margin area underneath the content block and the footer has a white background when it's supposed to be transparent.

Any help on these problems is much appreciated.