I am also having problems advancing past a segment of CoC:DCotE, in the Attack of the Fishermen chapter. My problem arises once I break the fan that leads to the sewers right after I evade the fishermen for the last time. I believe this brings me to the sewer part of the game. However, whenever I drop into the water, which starts the load sequence for the next chapter, the game crashes. Windows tells me the game .exe is what crashed, not anything else on my comp.

I have tried adjusting resolutions, as I have read that this is a fix for some portions of the game, but not on my computer I suppose. Nothing I have tried has worked. I'm getting fairly frustrated, as I'm realizing now I may need another game save to advance to the next part of this game. Which is a shame, because I have really enjoyed it so far. These bugs are draining me of my sanity, though.

My system specs related to this issue are as follows:
Windows 7 Professional 64 bit, quad-core processor, 4 GB RAM, ATI Radeon HD 5770 video card.

Thanks in advance for any help on this.