[Niklas Wikman] "The reason for asking here is that Aja does not specify iMac at all as "approved". But then again, FCP7 should run on an iMac, right?"
it is not approved because an iMac does not allow the user access to any type of external storage as the IoHD takes the entire FW buss to handle the video.
Since there is only one FW buss on your computer there is not a place to capture or playback the media from other than the System drive- and that is NOT recommended.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php