Problem installing liveries from PMDG's website

I have the latest verion of the MD-11 installed with Windows XP 64-Bit with FSX. When I try to install several liveries, the installation process proceeds as normal. However, when I enter the FSX aircraft select window, it shows all of the liveries I installed. I would select a particular livery, then a window would pop up saying that FSX was unable to display the model and there would be no visible aircraft. I have read a few post about theis particular problem. I have double cecked my aircraft.cfg files and each aircraft is numbered consecutively. I have completely uninstalled the aircraft and reinstalled, yet the same problem. I think it is important to note that this problem does not occur for each and every livery, but it does for about 60% of them.