I guess your problem is caused by Gecko's standards mode (Gecko is the rendering engine in Firefox), which renders space near images in a "proper" way, which is different than IE's. However, there is a special mode in Gecko called
"almost standards". You can try to add following lines at the beginning of you file- it should enable the "almost standards" mode
HTML Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
Or you may try to put something like this in your stylesheet (CSS):
Code:
img { vertical-align: bottom }