All the SM tutorials for download are DivX. I don't understand your issue... Well I do, but I don't understand why it isn't working.
It may be the G5 not liking the DivX codec, try this link and use this app for MAC Click Here
Chris (formerly R@nSiD)
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When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix
Winner SM VFX Challenge 1
3rd Place SM SteamPunk Challenge (May 2007)