I know that I.E. in its out of the box configuration displays images larger that other browsers. This you have discovered. I don't now enough about I.E. to know how to do it, but I'll bet there is a preference somewhere that lets you set the display type size. At any rate, it is an I.E thing that would need to be dealt with in the way that browser displays text. Of course you can't do this on everybody else's browser that views your site, so you have to take this into account and set up your styles and layout so they are not thrown off by this I.E. feature.
Re: different font size in different browser
--Kenoli
Re: different font size in different browser