NetStream.appendBytes

I have a netConnection connected to a Flash Media Server. I am trying to use the new appendBytes function from Flash Player 10.1 to stream a local FLV file to FMS. I'm having issues however... Documentation I get online

function playFile(data:ByteArray):void
{
// data is bytearray data from an already loaded FileReference object
    netStream.play(null);
    netStream.appendBytesAction(NetStreamAppendBytesAction.RESET_BEGIN);
    netStream.appendBytes(data);
}

However, I'm getting an error with the appendBytesAction and appendBytes. The error is: Error #2004: One of the parameters is invalid....

TypeError: Error #2004: One of the parameters is invalid.

Any ideas? Thanks

You can't use appendBytes successfully when your stream's NetConnection is connected to anything else than "null". From the documentation of appendBytes method at http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/NetStream.html#appendBytes%28%29:

Passes a ByteArray into a NetStream for playout. Call this method on a NetStream in "Data Generation Mode". To put a NetStream into Data Generation Mode, call NetStream.play(null) on a NetStream created on a NetConnection connected to null. Calling appendBytes() on a NetStream that isn't in Data Generation Mode is an error and raises an exception.

This almost certainly implies that what Adobe calls "Data Generation Mode" will not be available on a connection object connected to say, a Flash Media Server instance.