Thanks for all the thoughtful inputs.
I thought I might have had it fixed, I changed the workgroup name to something else, rebooted, and I could access the NAS! But I couldn't leave well-enough alone, and changed the workgroup again to what it should be, and lost the nas again. Tried rechanging the workgroup again back and forth, but no luck. The nas still shows up under "network', just can't get to it.
I am pretty sure it is something with network permissions, or something.
Now that I think back, when I put in my new router a few days ago, win7 found a "new network" and asked to join it. I chose 'home-type network'. Weird because my other win7 wired pc did not ask that....
It is some weird network glitch on this unit...