Newsletter problems with hotmail

[Wingred]

We have a newsletter that doesn't seem to be going through to hotmail and can't find any reason why. It's a subscribed list of recepients, generated by php using css to control the layout. The list is sent one subscriber at a time via php and does make it to hotmails servers where we lose track of it. We do have graphics, 5 jpgs, and links from the article intro back to the main article on the site.

The weird part is that it's gone through as much as it's failed. http://www.thetruthaboutcars.com is the site.

Any suggestons or ideas are welcome, we're running out of them.