I've been using Aperture for just over a week now, and feel it is really growing on me. Great management of photos. With one huge set back.... I keep getting 'Unsupported File Format' from time to time. Never with RAW (Canon 5D), but with my PSD files.
I've looked on google, and there are loads of people complaining about this, but Apple are silent.
I've done several things:
1) Rebuild Projects at start up holding the Option/Apple keys. But it just sits there and never completes
2) Rebuild Project per Project.
Interestingly, when I have a file that comes up with the dreaded 'unsupported file format ' error, I can open it in an external app such as Photoshop via Aperture, and save the new version, which doesn't contain the error message, but the original file does.
This appears to be some form of library database corruption. I know they had issues with RAW support for different cameras, but this is PSD files.