try this in your stylesheet, just to see if it has an effect:
div#navigation ul.nav ul {position:absolute; top:30px; left:0px;}
great, i just downloaded your css and it was working locally on my IEs, so we’re on the right track 
and in your supefish.js file you can adjust the speed of the submenus appearing ->
right now it’s -> speed : ’normal’,
you can let it drop down fast -> speed : ’fast’,
slow -> speed : ’slow’,
or take an value in milliseconds like this -> speed : 1800,

yeah, i see what you mean, but since this just happens when you F5 refresh the page, and not browsing from one page to another, i wouldn’t mind. But i understand you, stuff like that bothers me as well
maybe someone else here, reading this thread knows a solution?
jan
Have time now so i’ll try back tracking things i did lately. =)
quite often it is just trial & error, and a certain amount of suspicion hunting down the relevant part in the css (at least for me)