Admin section requires clear:both on bottom

The administration section is a very good piece of work, but I noticed that on certain themes the container does not expand vertically to include the admin blocks. I guess the problem are the floating blocks, so there must be a div clear:both below the container div:

<div class="admin">
......... // floating left/right blocks here
</div>
<div style="clear:both;"></div>

You might also use your own phptemplate_admin_page() function to fix this, but I think the default theme_admin-page() function must be fixed anyways.
My system.module patch attached.