Problems with template

I hade made own template for Drupal 6 for this way. Theme is very simple, you can see it in zip-attachment. But there are some problems with content position. Like that:

But standartn administer page have no problems

Can anybody help with this theme? Where i had made mistake, it simple but drupal do not want to work whis it correctly.
I think a lot of people see this problems, when they make their own themes.