Pete,
I tried what you suggested and in the PMDG NG, I get a blank cockpit when I move the PMDGoption.dll file out of the \modules folder and start the aircraft with FSUIPC 3.128. Move the PMDGOption.dll back again, and I get the cockpit back, but autopilot does not work. I replace the 3.128 with 3.125 and everything works again (as it has since I purchased and registered FSUIPC 3.00). Seems to be just this release.
I also tried to load the Simulation Software Workshop's A310 and I get a message that "wrong or no FSUIPC" is present, the a "Failed to connect to FSUIPC" message. When I replace 3.128 with 3.125, all works well again. I haven't been over to the SSW support forum and see what they are saying there, just repeated something I saw in my thread in the PMDG forum at AVSIM. I also have not tried the 3.128 release with any other "Complex" addon I have so may be affecting more than just these two.
Steve Park