Those two are XHTML transitional, Atahualpa is strict, it may be related to that
It's working on my test site, see
http://wp27.bytesforall.com/
Change the content in the Facebook text widget to the correct version
HTML Code:
<script type="text/javascript" src="http://badge.facebook.com/badge/514693422.570.1242595448.js"></script><noscript><a href="http://www.facebook.com/people/Les-Lamb/514693422">Les Lamb's Facebook profile</a></noscript>
(Note the added "type=...")
You also have a wrong <br> tag at the top of the twitter tag
</br> should be
<br />
If this doesn't help, try changing at the top of header.php
HTML Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
to
HTML Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
just to see if this would help. This should make IE less picky about other errors that may be on your site