Flash files won't work in any old directory?

Flash player 9 (and presumably all subsequent releases) have security features that limit where data and files can be accessed from.
Check the following directory (under windows):

c:\Documents and Settings\\Application Data\Macromedia\Flash Player\#Security\FlashPlayerTrust

Within will be some .cfg files, each specifying permitted directories for playing Flash (SWF) files.
Feel free to add your own,
i.e. file: mydir.cfg
contents: C:\temp

Will allow you to play swf files in your c:\temp directory