Pioneer BDR-206DBK and OS X 10.11.4

Just installed a brand new (2011 vintage) BDR-206DBK Blu-ray drive in my Mac Pro (Mid 2012) with 3.33 GHz 6-Core Intel Xeon processor and OS X 10.11.4

Drive plays all media fine but is mechanically erratic. Have tried it in both drive bays (with both sets of cables) with similar results.

a. Eject Button (and drawer) function is erratic. Sometimes it works normally four or five times in a row. Mostly it will not work at all, even after a hard reboot. When not working, the EJECT icon does not appear on the screen when Eject is keyed.

b. The "You Have Just Inserted a Blank CD" window randomly pops up on the desktop. This is when the drive drawer has not been cycled and no disc has been inserted. When the dialog window appears, it often cannot be closed without rebooting the computer.

c. Factory Apple Super Drive is in bay 2 and also does not respond to Eject command (Option EJECT).

Who knows what is going on here, please?