If you mean that the text in IE6 and IE7 is being cut off at the bottom of the left column on pages with a lot of text like current.html, then I don't see that problem; they show all the text.
However, IE6 has dropped the whole left column below the level of the right column, but previous.html is OK in IE6, so edit current.html to be like previous.html. The only difference that I can see without testing is that current.html has h2 tags in #maincontent which take the text further right while previous.html has no h2 tags in #maincontent.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.