I'm working with the Octopi distro  and it's supposed to have a few networking things already put together to make things easy out of the box.  One of them is an easy-to-use hostname and/or DNS name: octopi.local.  However it doesn't work.  I can't ping it or resolve it from a Windows 7 machine.  My Netgear WNDR3800 sees the name just fine in its list of connected devices.
I'm using a Wi-Pi for wireless networking on the Octopi, and have configured the file octopi-network.txt with my wireless settings.  I can access the Octopi's web interface from the Windows machine by using the IP address.  The Windows machine is using Wi-Fi as well.
I've already started another question on the Linux stack Exchange to try to get hostname resolution working on a different Raspberry Pi, and never got that working.
This question is different because Octopi uses avahi (aka Bonjour) (Here's a how-to) and all the docs and videos refer to octopi.local, thereby implying that we're working with a DNS name.  From what I can tell, it should work out of the box.
If I try to ping/nslookup octopi/octopi.local and it fails, what should I look at next?
On the Windows machine, I have tried to do an ipconfig /flushdns, nslookup octopi and nslookup octopi.local with no success.

avahi-daemonservice is running, and that it is not blocked by a firewall?