Weird line height with smilies

I just realise something weird. When I have smilies in my blog and viewing it in IE 6, the line height is smaller than the normal text, so the words seems squashed together. It only happens when there are 2 smilies in 2 rows together

I have this in my CSS body tag
font: 8pt/175% arial, sans-serif;

a screenshot if you don’t get what I mean

https://img32.imageshack.us/img32/4462/untitled16tw.jpg

you can see that the line height gets smaller, it gets smaller when there are more smilies. is there a way to fix it or something?

Thank you:)

I’m using wp 2.0.