INDYHALLLABS  Unfortunately, Apple has chosen to not keep their Core Animation libraries up to date for PPC architecture. The entire "Stadium" interface of Multiplex is drawn using Core Animation, and as such, excludes PPC users.

Given that Apple has decided to stop supporting PPC for it's next OS release, it was our decision to continue thinking forward and focus on maintaining currently supported systems.

We're sorry that you haven't upgraded yet, but we believe you'll find that you're going to be excluded from more and more new software as developers take advantage of Apple's new frameworks that they do not maintain for older systems.   
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SJK  > Given that Apple has decided to stop supporting PPC for it's next OS release

Has Apple publicly announced that?  
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INDYHALLLABS  SJK:

To be fair, Apple has not officially announced that they will be dropping PPC support, but the developer previews have been Intel Only and, as I mentioned, the PPC versions of Core Animation are out of date. If there's any chance of supporting PPC without sacrificing user experience, we'd love to do so.

We'll be finding out the details while we're at WWDC and if it looks like there's any chance that PPC will continue being supported in parallel to the growth of their Intel platform, and based on our findings we'll incorporate that into planning.  
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SJK  After recently getting an Intel Mac mini that'll run 10.6 I'm less bothered about it not being supported on my older PPC systems, which I've always suspected would happen. Hopefully we'll get the definitive word at WWDC. A lot more developers will consider releasing Intel-only products moving forward if indeed Apple drops PPC in 10.6.  
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