Did you see it?
This new release fixes a ton of thread issues, so we recommend you try it. Internally they changed the threading on Windows from fiber to full threads. While both are similar, some per thread things did not work well with fibers. I really hope this has no bad side effects, but I can imaging some plugin functions take advantage of the difference. Especially as in C you can have per thread variables which now will work properly.
For Mac OS X 10.9 Mavericks there are little fixes with app nap and redrawing issues.
Xojo 2013r3.2 is a free update for existing Xojo users of version r3.