This is a known issue (forgetting the number right now) - Linux-style locales don't work on Windows, and so there's a normalization function that has to be completely rewritten.

Also, since these seem to be on your own machine, I'm guessing your locale is not en-US? Please make sure you provide enough information for others to reproduce these - if they were occurring all the time, we wouldn't have got this far, so you've obviously got something configured differently.