You may have a race condition.
You are checking the status of your queue and then dequeuing the element in the middle loop. If that dequeue happens before the status is read in the lower loop, you have lost your message.
There are other things that could be improved in the picture you sent
1.) Not sure why in the second loop you just don't wire the dequeue item directly to the case structure.
2.) If you have a stop case, you do not need a local variable, just wire a true to stop.
3.) The exit LabVIEW vi is bad news. Do not use.
mcduff