CSS and Validation Problems – Please Assist!

I’m having some trouble with this blog: allirense . com / handmadewonderful (no spaces).

Everything was looking fine when I noticed that my top post didn’t match my bottom post (if you go there, you will see that right now the text on the bottom post touches the date box, but not on the top post. I don’t know how this can be when the style is supposed to be the same for all posts. I then created a third post to see what it would do, and what it did was, instead of the first post going further down on the page, it went up top to where the sidebar is supposed to be, pushing the sidebar down to the bottom of the page. I know why that is happening. I tried setting height to 100% in my css but that did not help.

I decided to try testing the validity of my page to see if that would find what was wrong. Testing the xhtml validity told me that I had a /div at the end of my footer that was extra; it wasn’t closing something. That /div is supposed to be closing my wrapper div. I even put comments at after each /div to tell me what they were closing! I checked my code and I couldn’t find any extra /div anywhere. (Note that I had found one when labeling them initially and I deleted it; there is a comment where it was.)

So, what am I doing wrong? Why do the posts have different margins at the top of the text, why are they going to the right instead of continuing down, and where is my rogue /div?