Earth Initiation - Cannot leave the castle anymore

[qwerty123]

Hello,

I just finished the Earth Initiation and beat the mage, now i cannot leave the castle anymore.
The complex consists of a main house and a park in front, all encircled by castle walls. There is one entrance in the walls that leads down to the village.
I can freely move around the complex, but as soon as I click any location outside the complex, the green circles marking the move target quickly flash up, disappear again and the party stands still.
Here are some other weird things i figured out:
- When the party is inside the main house or one of the guard towers on the wall, I can mark locations outside the gates again, but as soon as I leave the building, the bug shows up.
- If I scroll down to the village and mark a Spot inside a house as move target, the green circles correctly appear, but the party doesn't move anyway. Additionally, the frame rate goes down to about 5 for a short moment.
- and, if it's any important, a dead enemy is lying right in the castle exit. Normally, enemy bodies don't pose an obstacle, do they?

My specs:

Intel Core i7 920
6 GB RAM
ATI Radeon HD 4800 Series
Windows 7 (64 Bit)
Steam version of A Farewell to Dragons (v1.0)

Savegame is attached.

Thanks in advance