I'm not a Flash/action script guy, but I see that your error specifies a different file than what you show in your code. Is it a typo or a problem?:
sfcflash\sfc.xml
osfcflash\
osfc.xml
I've also seen a few sites mention how Flash opens files locally. What location do you run this script from? Is it the same location as the xml file? If so, maybe try:
Code:
menuXml.load("osfc.xml");
Unfortunately, I don't know much about Flash. Last time I touched it was back in 1997...and I didn't get very involved with it.