How many times I saw the same behavior >:(
Do not delete the Symantec driver. Do this:

  1. Copy one complete entry of avast! and put it in the first line
  2. Press enter
  3. Let the Symantec driver at the end…

I just can imagine that the Symantec driver block the entry of appended data. avast! try one and another and another… The values were blocked by a double group of zeros at the end of Symantec entry. It’s not allowed to an application to block that general key! But Symantec do it! >:(