Why is IE7 rendering these differently?

Question

I'm totally baffled as to why these 2 sites are rendering differently in IE7, even though the theme powering both is the same, they're both on WordPress 2.9.2...

This one is okay: http://htm2wp.com/dev/svn

This one has the sidebar appear at the bottom: svnsvadvisors.com/blog

Meanwhile, they render the exact same in Chrome and Firefox.

Anyone have any idea why this is happening? I think I may just be too close to the problem to see it.

EDIT: I've imported the same posts into the htm2wp version, and now its broken. So, I've got another hint.

FINAL EDIT: It looks like the problem was caused by the titles of a post being too long and increasing the width of that one box, throwing everything off. So, yes, while the page doesn't validate, it looks like its not a validation error.

Answer 1

According to the W3.org validation service, the first site has 40 validation errors, the second has 55.

Malformed documents will screwup IE7 for sure. Fix the code, make sure it validates, then check the rendering in IE7.

If the rendering is still not what you expect then its probably a CSS problem.

Answer 2

The template file in use for svnsvadvisors.com is likely missing its tag, as the page source doesn't show </body> or </html> closing tags and the eror report shows lots of missing ending </div> tags:

[Invalid]Markup Validation of svnsvadvisors.com blog - W3C Markup Validator. Scroll down in the validation report to see line numbers and source code.