As for my problem it has to do with the comments template and single pages shifting to the right when there is a comment box. I am using the basic comment template that was in the starkers theme. The problem happens in firefox and sarfari but seems to be ok in IE7. If I remove these 2 lines from the comment template it doesnt shift the page but it obviously takes out the comment box and submit button.
It had something to do with the length of the index page. I created several test posts to increase the height of the main column and this fixed the problem. I read somewhere it had to do with the scroll bar.
I am still unsure how this happened but I guess it will be a problem until I get more actual posts.