Hi Michael,
I finally got the approval mechanism working! The dispatcher option "Evaluate approvals" was not checked (under "Policy" tab).
...and also make sure that you are running the latest version of DesignTime and Runtime patches
and that you also updated your Database (mxmc-update and mxmc-enable-72-approvals scripts).
Please try this and let us know if it resolved your problem.
Cheers!
Marco