Issue with PMDG Delta 800WL Livery

I've been trolling about Europe with my shiny 737NGX - This aircraft is so good it should be bad for you. I love the simulation, and was one of the first PMDG 737NG (FS2004) owners when it came out as well.

Using the Delta (Ribbons) livery, I've had repeated issues with deceleration on descent, autopilot disconnects, and other strange little weird issues with the A/P and the flight mechanics. So because I know it by heart, I flew the box-stock model in the Tutorial 1 flight and this Delta bird as well in the same flight. The PMDG House 800 w/ winglets performed as smooth as silk, and everything worked, although I had a strange glitch in the CDU/FMS that I'll describe below. The Delta jet failed to make the descent in all 3 flights. I had 2 AP disconnects (uncommanded), failure to reduce airspeed as programmed in the FMS on every flight, failure to fly the FMS SPD as programmed and a constant drift to left even though the wx was set for clear skies/no wind and the trims were centered. The drift could not be trimmed out. EPR/thrust appeared to be asymmetrical as well, even with N1 and N2 reading identically in both engines. ( I realize, as both an A&P and as a former USAF fighter fixer, differential thrust can exist in the real world even though both engine RPM's or EPR are the same on the gages)

The KLM, Virgin, and Southwest (Warrior One) aircraft performed as expected, except for the same FMS/CDU glitch as the house model.

I've searched the forums about this issue with the Delta livery and found nothing. Might just uninstall and reinstall it.

As for the FMS/CDU issue, it's a sidebar in this post and no, I haven't searched the forums yet for this one.

Two consistent items with the non-Delta aircraft as it relates to the FMS/CDU:

• As I'm midway between the transition alt at 060 and cruise at 250 on the tutorial 1 flight approx 5-6 nm before ARTOV, all of my airspeed/alt references on my LEGS page will go blank, and then repost.
  
• As I'm in the descent just before EH606, I sometimes get the message DESTINATION PATH UNACHIEVABLE, and then it goes away. This is on all the aircraft that are NOT otherwise having issues.
  

Only the Delta (Ribbons) livery is having major issues. Does the various "real world" liveries (duplicate cockpit to real world tail #) actually have different systems or flight mechanics? Other than the different MCP's and having/not having the HGS or stby ADI...

Please advise.

Cheers.

Kev