I was trying to start a new game but during the execution the dragon just keeps circeling the tower with the headsman staring at me unmovingly.

I can't go on from there.
This happened after the last path and the installation of two mods: The Space Core thing and another one that adds waypoints for the player homes.

Other things installed include SKSE, SkyUI, Categorized Favorites.

Have you, or any of your mods affected the timescale?

Any timescale less than 5 will cause this to happen. I've no idea what the Space Core thing is... does it affect passage of time?

that's the space core: http://www.youtube.com/watch?v=f9H8jo1XKDI
and as far as I know none of my mods need to affect the timescale.

anyway, i restarted the game without the SKSE script extender and it worked again.
still, it worked before even with SKSE running, so I assume that the latest path interferes with SKSE.

Any time the game updates you should disable ALL mods. The mods themselves will need updating to the latest game version or else issues like this will arise.