Sidebar menu drift

Hi folks,
I have got a bit of an issue here that I am not sure how to fix. I work at a community college that contracted out to have the bulk of the site built a couple of years ago. Well there is an issue were the sidebar navigation menu drifts downward when there is a lot of text on the page. My colleague and I have been trying to fix this problem now for a couple of months. We “fixed” the problem in FF and Chrome by removing some div tags, but the drift is still there in IE. I have also been able to “fix” it in FF and Chrome by defining a rowspan in the table but it is still bad in IE. I am thinking it ahs something to do with a float or position tag somewhere but I can not for the life of me figure it out.

Here is an example of a minor drift
Here is one that is “fixed” in FF and Chrome but not IE
Here is one with no drift (built by another 3rd party