trouble reconnecting to mapped drive RN212

I'm unfamiliar with the "parameter is incorrect" result.  Did you save the login credentials when you created the mapped drive?  I don't, which may be the difference.

As far as the NAS showing up in Network but not being accessible when double-clicked, that's a problem some of us see and others don't.  I've seen similar postings regarding other NAS brands, so I think it's a Linux Samba and/or Windows issues, not one Netgear can solve.  I hope one day somebody will get to the botttom of it.

The best work-around is to add the NAS IP address to your HOSTS file on the Windows machine.  You can Google how to do that.  Note that that does require that your NAS always have the same IP address (which is always a good idea, anyway), and that is best accomplished by reserving an address for it in your router than by using the static IP capability of the NAS OS.