I have the FSLabs Concorde X. This aircraft almost brings my system to its knees, stutters, difficult to hand fly, the trimmer was non-existent. However, due to my love of the aircraft I stuck with it.

The other night, after a typical jerky, stuttering flight, I was descending into Bahrain when I heard a windows "bing" but thought nothing of it, I did notice that FSX smoothed out, the FPS increased, and the controls of Concorde became almost dream like.

I went to my title bar to go into the Add on menus and realised my FSUIPC had gone.
Experimenting today I un-registered my FSUIPC and it has solved all the issues with Concorde.

Now why the dicky-devil would that happen?

Paul