Flex project: detect CSS changes when compiling

In my Flex project changes to CSS file are not includes to the compiled application swf.

After changing the mxml node source in

<fx:Style source="../style/sample.css" />

to

<fx:Style source="../style/sample_test.css" />

and back again, changes are visible in the compiled application.

Anyone else got this problem or is there something wrong with my setup?

I'm using IntelliJ IDEA 11.1.4.