I've been using Flash for years but I only just recently upgraded from CS3 to CS5.5 and I see that if I render my movie out as a PNG sequence it also renders my guides. I've rendered PNG sequences several times on othe projects and never encountered this before.
I've since discovered that if I simply hide my guide layers I can render out the image sequence without the guides showing, but I'm wondering if this is a setting I can changed. I like being able to see my guides while I'm working, I don't like having to turn them on and off if I'm going back and forth between animating scenes and editing them.