I have been finally able to produce a crash under wine, and found indeed another place where the pixel addressing in the crop module was wrong, which I fixed. Hopefully this is the same problem you observed, and this new version will fix the crashes for you as well.
Please give the new version a try. If you still observe crashes in the crop module (or any other crash by the way), you can try to run photoflow.exe through the gdb.exe debugger that can be found in the same
bin folder, and send me the stack backtrace.
The RawTherapee documentation has a very nice description of how to use gdb under Windows and how to generate a stack backtrace of a crash. Adapting the instructions to photoflow should be rather easy, but do not hesitate to ask for help in case something is not clear. The photoflow package I am shipping already contains debugging symbols, so you do not need to download a special version in order to run gdb.