HTML Question – stumped

My site looks fine in Firefox, but not in IE. I’m not hep enough to know all of the peculiarities of this (unfortunately ubiquitous) browser and I would be extremely grateful if someone could look at the source code and tell me where I’m going wrong:

1.
There is a vertical black line in the upper right quadrant of my homepage in IE. I ‘d like it to go away.

http://crisispictures.org/index.php

2.
The content in in my category and single post pages doesn’t center properly in IE. I’m, once again, stumped.

The pages look fine in Firefox.

Yes, I know I could do this much better in CSS. I’m new. I’m doing this site as a nonprofit service and am doing my very very best.

Your help would be appreciated.

WARNING: Some of the images on this site (which shows unpublished images of humanitarian emergencies)_ are upsetting.