SWF has higher framerate than specified in the compiler arguments

I compile a SWF with ANT using FDT. In the compiler arguments I am setting default-frame-rate to 30. When I run the SWF, the stage.framerate property is 30 (which is correct), but as the Stats util from mrdoob shows, the SWF runs way faster – up to 52 fps.

So it seems the compiler argument default-frame-rate is applied, still the events are fired at a higher rate开发者_如何学Python. How can that be?

These are the compiler arguments:

compilerarguments="-target-player=10 -swf-version=10 -default-frame-rate 30 -default-background-color=0x000000"

Unless gthmb is correct, something, somewhere is setting stage.frameRate to another (higher) value.