convert to mono problem

Hi in Soundtrack Pro my computer (Mac 10.6.8 3.06GHz Intel Core 2 Duo w/4GB 1067 MHz) howls when I convert to mono. This, even though I have a firewire output to M-Audio 410. Has anyone any clue why this is happening and what I can do to correct it?

Thanks,
Daniel

What do you mean by "Howls"? The Mac physically howls; the output audio is a howling type noise.... ? The devil is in the details..

Thanks
Gary Sumlak
thumbprints Multimedia Inc.
Edmonton, Alberta, Canada
[www.thumbprints.ca]

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