Just a heads up to anyone, yesterday evening, I updated my Parallels 4 install to Parallels 5 since it was suppose to offer speed enhancements (which it definitely did quite noticeably).
However, PlayOnline will crash now under Parallels 5 due to the display adapter driver. Rolling back to a non - WDDM driver will make Playonline work again, but I can't get my FFXI to start without the direct x error after it attempts to move over into fullscreen.
Just as a warning, stay in Parallels 4 if you use it for now until this issue is resolved by Parallels.
Bug #: 456588
More information about the problem can be found here: Final Fantast XI stopped working - Parallels Forums