You’re probably a special breed if you’re reading this. The nuance of this feature along with Flash’s implementation peculiarities mean that most people just don’t fool with it for more than ten minutes.
This one bit me before, so I’m making a note to myself:
If you’re using StyleSheets in Flash via ActionScript (I didn’t try loading a textfile), the kerning property does not take a Boolean true/false as the documentation insists. I only works if you use a Number 1/0. The font tag will let you use a Boolean.
Also, since you’re so special, I have a tool I’ve been working on to compile fonts into loadable libraries on the server. It will attempt to include kerning information if possible. The only other way to do that (to my knowledge) is via the Windows IDE.