Hey everyone, I ran into this problem myself yesterday and I may have a solution. The difference for me is that mine worked just fine for a good two months. Yesterday my entire box locked up while playing, and when I rebooted, FFXI would crash the entire VM when I hit the character selection screen. I tried re-installing FFXI, re-installing Parallels, and even running the "SFC /SCANNOW" command in Windows 8 to determine whether my direct X files were corrupt.
None of that proved helpful, but I ran across a comment where someone said to change the VM Optimization settings (Virtual Machine->Configure->Options->Optimization->Power) to "Better Performance" because otherwise Parallels would choose to use the internal Intel card that's meant for power savings on newer Macs and NOT use the high performance card. Well, that didn't help, however, I went one step further and went into my System Preferences->Energy Saver and uncheck the "Automatic graphics switching" box.
After that, I was able to log into FFXI again in Parallels. My guess is that something broke in my OSX internals when the system locked up...not too concerned about fixing it long term, as I know how to work around it now. Try this..and let me know if it helps you guys.
Good luck!
Waverly