I just downloaded IE6 yesterday to fix a small but crucial problem, and noticed the same thing. To temporarily (and nastily) fix the issue, I created a CSS file with the following line:

TD { text-align: left; }

And then I told IE to use it as my style-sheet by going to Tools->Internet Options. On the General tab, click on the Accessibility button. Check off "User Style Sheet" and point it towards the CSS file you just created.

Sure, it sometimes overwrites the alignment, but it's better than having everything centered.