Whenever poser acts strangely for no apparent reason, it's usually because of a corrupted Prefs file.
Simply delete the Prefs files and re-do them, this is usually sufficient to stop all weirdness except for the need to spend!
If you need to know how to do this I have posted it many times in the forums, not sure if it's different for a MAC though!
If you can't find it here, search at Smith micro knowledge base using the term "Prefs" and it will find it.

Injustice will be avenged.
Cofiwch Dryweryn.