I had a very strange bug and think it’s so hard to find that I post it.
In my last project I had to load external graphics and I got the URLs out of a database via Webservice and Fluorine. The bug was that the images where loaded in Flash Player 9 but not in Flash Player 8 or below. The project was targeting Flash Player 6 so when testing with FP9 the AVM1 which renders content < FP9 is used. So with FP9 and FP8 a Flash Player 8 is used to render my swf. What can be the difference? At the end it turned out that the database stored the URLs with a space character at the beginning like " myimage.jpg". FP9 with AVM1 seems to trim the URL but not FP8 or below. Now that was a fun to debug!