I just installed Frame 7.0 on OSX 10.5.5, and it seems to work quite well (It required me some time to configure CUPS to use A4 paper as a default instead of Letter as a default; the settings from the print dialog weren't recognized).
One other obstacle remains: how can I save as PDF - an error message 'FrameMaker could not find Acrobat Distiller printer Instance' appears. Is this a known problem and has somebody a solution?