Greg
It looks like the issue might be related to the password change failing. When I turn off complex passwords, I have no problems. However, when they are turned on and I provide a password that I know won't work (like one that includes the user's name), then when I click on OK, it just sits there, does nothing.
I have not noticed that, I do the same (turn off complex passwords) and works, I think the problem is not in my code.
An small detail, I use spanish, so my application has localization, must things work but in the Change password dialog there is a small problem, I add an screenshot with the text that is not localized and the translation, hope SF could add this in next update.
Regards
Everything is possible, just keep trying...