Ok, I've had this problem several times before and I've never been able to solve it.
It only seems to happen in IE...
http://www.babes-for-fun.com/100gals/sammy4u/
You see that the spaces between the thumbs decrease in size if you go from left to right. If I remove the black text in the center of the ad at the center of the page all the spaces between the thumbs are the same again but as soon as I start typing text and it jumps to a new line the <td> the text is in just gets smaller.
FF doesn't seem to have this problem..
Anyone?