Whenever I try to move to the south-east part of Emerald Lake the game consistently hangs.

I have explored the rest of the lake and have finished the 'Lost in the Swamps' quest, but I cannot explore that part of the lake.

Has anyone else had this problem and if not is there anything important in that location that prevents me from finishing the game?

Edit:
If I switch the Graphics Engine to Open GL the game does not hang but gameplay is stuttering a bit. At least I will be able to explore this part of the gameworld (and afterwards go back to DirectX).