Have you tried not using the <br>'s for your buttons there? Looks like IE is having possible conflicts with them for some reason.....how about putting the HTML code into a {codebox} so we can see incase there might be a little typo, or coding error on your part in there?
(regarding the left-column buttons, they should automatically line-up vertically if you specify a max-width with a display:block; no?)
(regarding the left-column buttons, they should automatically line-up vertically if you specify a max-width with a display:block; no?)