<div>'s vertical expansion problem

Hello,

In firefox browser I am having trouble with my <div>'s not expanding out height-wise appropriate to its content. Sometimes it does, sometimes it doesn't, depending on the refresh. All other browsers seem to work fine regarding this. I have attached 2 screenshots to help explain. Any ideas on what I need to set this <div>'s style to to accomedate this appropriatly in FF?

Wrong: http://img46.imageshack.us/img46/226/wrong1hx.jpg

Right: http://img46.imageshack.us/img46/2955/right6rb.jpg


Pages where this is seen:
http://www.websolvents.com/forums/

More prevelent here (click around on the links, knowledgebase, etc):
http://www.websolvents.com/members/



Thanks again!

Kyle