I would use camtasia 2... disable the hardware accel. and
then do a full screen recording of your SWF. From there, take the
AVI file that camtasia makes, and encode it with
SUPER encoder,
which converts any type of media to almost any other type of media.
I've been using this since April to convert movies (specifically
DVDs to iPod format), and occasionally I'll have to make an
FLV.