asterisk users - Dec 2010 - MixMonitor not recording in version 1.8

Greetings.

Just updated from 1.4.22 to 1.8. Minor changes in dialplan and things work
ok. Except for one thing.

I have a call to MixMonitor. This is implementing a dictaphone kind of app.
With forwarding recordings to email and storing them on the server.

The process works so that we dial into Asterisk and answer the phone,
initiate MixMontior and WaitExten until recording finishes.

Problem is that in 1.8 the MixMonitor does not begin recording, ever (when
applied as shown below). I've tried MixMonitor on the same server with
bridged channels and this is no problem and works as expected.

Question is, is there a way to force MixMonitor to work on 1.8 as it used to
on 1.4.22?

Dial plan (AEL) is as follows (excerpts):

// BEGIN OF SAMPLE ************************

incoming {
	5559999 =>  {
		jump 0000 at dicta;
	}
}

dicta {
	0000 => {
		Answer(1000);  // Slight initial pause to allow audio to
balance

		Playback(beep);

		// ***************************************************
		// THIS IS WHERE the problem lies.
		// This call does NOT start recording at this time!
		// It used to work, in 1.4.22. But in 1.8 it does not.
		// ***************************************************
		MixMonitor(myfilename.alaw,,mv myfilename.alaw
myfinishedfilename.alaw);

		jump 0001 at dicta-while-recording;
	}
}

dicta-while-recording {
	0001 => {
		WaitExten(400);	// This is effectively the maximum length of
a recording!
	}
}

// END OF SAMPLE ************************

Any help is greatly appreciated.

Best regards,
Baldvin