AJAX registration layout mesed up in (older) IE

hi there,
i have an AJAX registration form on my website which runs fine on basically all new(er) browsers but some of my users reported problems with the layout being messed up and fields mis-aligned.
I have been able to re-create this issue in IE 9 AND the compatibility view switched on ....
see www.relativerotationgraphs.com registration form.
Any clues on solution or workaround ?
thx, Julius

Compatibility view turned on basically gives you IE 7 which nobody supports any more. Anyhow, you can play with CSS to make it look correct even in the browser 8 years old.

i know what to tell them

no way i;m going to put work in css formatting for 3 occasional users... i'll put a note saying that thet really need an up to date browser ....
thx