weirdboy: I was running into this issue while trying to enter certain buildings, and this link to the other site helped me sort things out. The specific post that I referenced was
this one and the one a bit later with another file. I just download those files, renamed the old versions of them in the install/data directory, and replaced them with those versions, and now I am able to enter the building where it was crashing every time previously.
waltc: Thanks for the tip! I installed those files and suddenly I'm hearing my character's voice in-game for the first time (oddly enough)--sound seems to have improved 100%. Still crashing some when entering/leaving a building, but reloading always gets me beyond that point so it isn't a show-stopper. I had the 2-cd version and apparently some of the files were not decompressing properly during installation. I can only wonder how many more files may be corrupted--but the game is fantastic overall in WIn8Pro x64 @1920x1200.
edit: version 2.20 of the widescreen mod seems to have corrected my crashing problem so far!
edit: aqrit has directed me to the 3.06b version of the Widescreen mod--which solves the problems that 2.20 fixed that were brought on by 3.05. It works great, and is the version to use--2.20 is too long in the tooth...;)
Edit--forget it--if anything the 3.06 WS beta is proving worse than the 3.05. What a mess.
What I ended up doing was replacing the guts of the 3.05 widescreen mod with the changes that were on github (which does not contain a new exe), and running that Frankenstaller. That seemed to clear up all of my issues and I have subsequently put 20-30 hours into the game with nary a crash. It has been long enough now that I don't remember precisely what I did, but the steps in this other GOG thread here sound pretty close: