The localization issue was particularly insidious. What was happening was:
1. The app would do its initial startup and load in stories from the Twine/Stories directory, creating it if needed. This step would ask the localization code to translate the name "Stories", but because localization data hadn't been loaded yet, it would fall back to translating it to "Stories", no matter what langauge you wanted to use.
(The reason for this fallback is so that if something gets really messed up, you can still at least get some words on the screen, even if they're in a language you don't speak.)
2. The rest of the app initialization would occur, including loading localization data.
3. A user would make a change and Twine would try to save it to that Twine/Stories directory... only this time, it would translate the folder name. So if you speak French, for example, it would try to save to a nonexistent Twine/Histoires directory and fail.
The solution was simple -- load the localization data as early as possible -- but it was tricky to diagnose.
Looking at the release notes page tonight, I realized the last release was about three months ago. I think we're on that pace, roughly, for future releases as well -- perhaps a little bit faster.
I'm also working on Snowman 2.0 and am close to a release on that, which is exciting. It's not too too different, but I am changing some syntax, most notably the way you create <div>s and <span>s (which is buggy in the 1.x series).