To follow up on my own post:
I rebooted my phone, and after the reboot, it did detect the server.
Then the windows machine popped up an entry, "a new device is trying to access your library, should you accept it".
I said yes.
After, this is what the accepted devices look like.
Note that number 2 and 3 are both my HTC evo phone. Entry #2 is the one that worked when I synched my music last Sunday. But stopped working today. #3 is the one that was just added and seems to be working.
I found while fiddling that there seemed to be no way to delete an entry from that list. I looked earlier to see if I could remove the old EVO entry, to try a new scan. It would be handy to be able to reset entries.