Problem with FadeIn() while the text is fading in IE7,IE8

Problem with FadeIn() while the text is fading in IE7,IE8

I got a problem with FadeIn() function in IE7, IE8.
The problem is when the text is fading in (not after faded). It got a bad quality font like you can see below. (the text color is black)



This problem appears oviously when the text size is 20px. I found one way to solve (setting the background color of the text). But what about any other ways without setting the background color ?

I have tried removing ClearType (before and after, before, after animation). But it doesn't take any effects.

Thanks in advance
and sorry for my bad english grammar :P