@Atomic: thanks so much for the willingness to help, but I've signed a NDA for this project, and can't make any file avaiable for now. I'll try to reproduce the problem at home this weekend if I get some free time.
@turtelly: Nice to know that. I checked the versions and they're all flash 7, though =/
To anyone that is interested, the solution I used was a mix of what ppl said here on the forum. Apparently, both rendering text as HTML (Dynamic Text Fields) and setting it to use "Device Fonts" force the text to be aliased.
In my case, since the text fields didn't have any style variations (size variation, bold, italic, etc) I converted it all to dynamic, multi-line text fields, using Device Fonts.
Thanks for the help, guys.