After some puzzling I discovered why my xnview kept crashing on a certain folder. It seems I accidentally renamed a .jpg to a .raf (fujifilm raw file) at some point. This caused xnview to crash while indexing the directory. It also prompted a data execution prevention by windows xp when I tried clicking it in explorer ( I have the right-click thumbnail preview by xnview enabled in windows explorer, so I think this is related).
After I figured out how to isolate the file on the command prompt, I renamed it to a jpeg and everything is ok again.
So this is more a robustness matter then a bug. Everything works OK and the error was on my side. I know of programs that can determine which codecs are needed for movies and such, I bet the same exists for image files. Perhaps xnview can check and report a faulty file data\extension combination and prompt to rename it?
OR.....more to the source of the problem, warn when files of different extensions are renamed to files of the same extension.
In case you are interested, this is the error report generated by windows
edit: it seems I can't enter this here
