Delane,
I could have sworn that I saw somewhere in the release notes that the most recent version of PM5 was compatible with PhaseOne IIQ files. Was I wrong?
There is indeed support for IIQ files, but don't expect much. PM will recognize the files, show you thumbnails and very small previews, and allow you to do soft edits (tag, rate, color-class, rename, and crop) but the IIQ files do not contain high-resolution previews so you cannot view high quality previews.
If only PhaseOne would write out higher resolution previews...
-Kirk