The sites in question are:

http://riversideprep.net
http://orogrande.org
http://about.riversideprep.net

First issue: Drop-down menu for the page menu bar falls behind the post content area, so navigation is impossible.

Here's an example.

This issue does not exist in Firefox or Safari in OS X. Any ideas as to what is causing this?

Second Issue:

Margins are all jacked up in Internet Explorer, but look fine in FireFox or Safari.
A good example is here, where the image is cut off, instead of overlapping.

Here, the blog title is stuck behind the logo.

Third issue:

No flash video content will display in IE (I understand this may not be an issue with Atahualpa, but it's worth the mention)

So, did I do something to break this? I'd really like to get this fixed quickly. Thanks in advance for any help!

I would gladly donate if I could get a fix for this issue.

Hi - just letting you know that I don't see an issue with IE 8. I have experienced an issue using Flash before and had to resolve by making an animated gif instead.