Code:
var fo = new FlashObject("vbflashheader.swf", "vbheader", "800", "150", "8,0,0,0", "#e1e1e2");
This is the same in the forum directory and outside it.
If it's pointing to a relative location (I'm going to assume it is) then it can't access the file from outside the directory because it's inside it!
Easy fix:
Place the flash file both inside the forum directory and outside it.