I have tried two of these in my NV+. The result was a non booting NV+. This memorymodule should be removed from the compatibility list. The user 'geekstarpilot' experienced also the same problem with this module. On the internet are more posts regarding this module using the Readynas DUO (also with problems).
So I do not recommend using this (I guess the current revision is somehow a bit different compared to the ones which other users are using with success)