I see no one has replied to your post. If you have not received an answer yet, I found a bug report about the exact same issue from back in October 2009.
http://bugreports.qt.nokia.com/browse/QTBUG-5032

Since there can be more than one active state they have this function.

QStateMachine::configuration ()
You can compare the objects themselves if you have the list of your states handy. Another way is to name your states and keep the list of names for comparison.

(Why this function is not called activeStates() I don't know. )

spawn9997