Hi Funky,
Apparently Garter Snakes floats up to where Boas is because of the float left instruction in your CSS tag for that element. You must remove that tag for the vertical alignment you desire. Do not use non breaking spaces for this, the first line will be positioned strangely due to this.
The cross browser issues are due to IE hover issues: you could resolve this by identifying the list element by id and changing its visibility through Javascript using the mouseover and mouseout events. I'm not sure about a way to do this in CSS, but I am sure of the other way.
--Russell