Reprint Label not working -- it's reprinting a Packing list instead

Hi,
I have a Smartpost shipment where the label was created but did not print. I also printed a packing slip for that order. Now when I hit the reprint button for the label, I keep getting the download of the Pdf packing slip. I tried the reprint button on the righthand menu while the order is open, and also the reprint button that shows in each listing in the full list of shipped orders. Both will only reprint the packing slip. What am I doing wrong?
Thanks!