Currently Being ModeratedJul 8, 2012 8:15 AM (in response to bws5)
The Upgrade to Aperture 3.3 is a major new release. Aperture 3.3 requires Lion - MacOS X 1.7.4, and will only run on Macs with 64bit Intel Processors. If you upgrade to Aperture 3.3., your Aperture Libraries will be converted to a new format, that is incompatible with earlier Aperture versions. You will no longer be able to open these libraries on your older iMac. Sorry.
and the Aperture 3.3.1 release notes
Currently Being ModeratedJul 9, 2012 12:17 PM (in response to léonie)
I have a similar problem, except the fact that my Lion mac already has Aperture 3.3 installed, while my other mac in incapable of running Lion. Hence I seem to be stuck with two incompatible versions of Aperture. Is there no way to downgrade from Aperture 3.3? I have not yet upgraded my Aperture library.
Currently Being ModeratedJul 9, 2012 12:26 PM (in response to kristomi)
As long as your Aperture library is still version 3.2.4 and you still have an installer for a previous version of Aperture 3, plus the serial numbers, you can just delete the current Aperture version (aftner making a backup) and reinstall.
How did you buy Aperture? If you bought from the App Store and did not keep the installer, you are stuck with the current version (unless you have a bootable clone of your pprevious system), you only can download the most recent version from the App Store.
Currently Being ModeratedJul 9, 2012 12:30 PM (in response to léonie)
Thanks. Yes, I bought from the App Store, and I do not have any installation file. I tried to download a trial installation for 3.0.1, but since Apple discontinued the trial program, I can't seem to get a serial to get it working. I really dislike having such a "simple", yet hard-to-fix problem.