Thnx for the fast reply!
Seems that when switching to P3Dv4, my FSX uninstall got botched, maybe there are some residual FSX registry entries still around. I will look for them and remove them.
Curious however when installing GSX again the FSX entries are blanked out, only P3Dv4 was enabled in the install window.
Edit
Seems to be working now. Live update is running!
Thanks for the help!