9 - slice issues

I have been playing around with the 9 - slice function. unfortunatly i can’t figure out why it doesn’t work with jpgs / pngs … works fine if its vectors only.

I saw this example that seems to be jpg or png . I am not sure .

thanks for any info .
[url=“http://weblogs.macromedia.com/xd/archives/2005/08/flash_8_and_sca.cfm”]
http://weblogs.macromedia.com/xd/archives/2005/08/flash_8_and_sca.cfm