To clarify, when you view the executing workflow on a RITM, you see the both the Approval - User and Catalog Task activities in Blue / Finished?  And there is a blue line going from both of those activities to the Join activity?  And the Join activity is blue, green or uncolored?  You'll probably want both the Complete and Incomplete conditions going to the same next activity as the join is only reached if the Catalog Task and Approval are completed.