I've just installed sigil 0.1.9 today (Windows Setup.exe). I downloaded and installed today and have had the same problems on saving.
Sometimes the save works great, others the save crashes the program without saving. I was working on "split" mode both times when saving, if that helps at all.
Where do I post comments and suggestions about feature changes, by the way? I haven't weeded through all the posts to find that information yet.