Contour single DRV not whole house

After having my original dvr keep showing error dui, Cox sent a tech out to check the issue.. Tech stated that the signal to and inside residence was "great"...  Advised me to swap out the box to a newer model...  I upgraded to the Contour  service not the whole service house just the one TV...  Since the "upgrade I have been getting errors 2.1.2.7, and 2.1.2.1 ... The tech stated that they have no idea what goes on in the dvr, but still advised the swap for a new box..  If these errors stem from the CISCO recall from way back in February why hasn't Cox removed all " defective drv's " from service ????  As a long time Cox customer since the 70's this is the most trouble I have had with Cox equipment...