I have a pixel font problem on Flash CS3 on the mac. They are not well readable, I tried every setting. In Flash 8 it is ok. I'm using fonts for flash fonts. It's like 1/3 of the font is slashed off.
Looks to me like you have too little linespacing - or in case those are in their own textfields - these are not high enough to show the desired font size.
Just guesses - Adobe hasn't brought me CS3 yet (promised me to have it march 1. Now that's service hehe)