Flash Develop: Compiling SWFs (External or Popup)

I'm one of those who, to quote the BritishTelecom ad "have gone back to FlashDevelop". Its just a wonderful IDE.
***However there is a point to note. While selecting the Debug options for viewing your swf's. The player used for the Popup option, seems to suffer a performance hit against the player used for the External option. I compiled a swf which seemed to really struggle when I used the Popup player but ran smoothly when I viewed it in the External player. I'm trying to find out why this is so.


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