exporting from livetype without a background

I have some headers I want to bring into flash from livetype -- but I want them without a background -- I have them without a background in livetype but when I export, they always come up with a solid background, even if I export in a quicktime mode that allows millions+ of colours -- if I create a livetype file with a transparent background, does that not automatically create the alpha channel or do I need to do something else? Then how would I retain that channel when exporting in a format that flash can then pick up?

thanks in advance!