it is already well know that going anywhere there are a large amounts of AI units to generate can cause your game to CTD.
Dunkirk is one for sure as not only Mines but also a large amount of shipping to generate can CTD the game. when I used my old rig I could not go anywhere near Dunkirk but with the new machine I can get in there and fight.
Also approaching a large convoy also CTD my game with my old system.
so you could say it was because of GWX as it generated more AI units in that area then the Stock game but the truth is my machine could not handle all that information simply as that.
See now my post are in two diffrent colours
Edit.. Wow thats was strange