@NecroCorey When you go directly to it that way, it can sometime rebuild the master browser tables.
To be honest, Network Neighborhood has always been flaky (especially in the Windows 98 and XP days) so I always just type in the name directly.
I despise the backslashes since everything else in the world uses forward slashes. I think it was just baked into Microsoft stuff for so long that once the WWW appeared, it was too late to change things.
If you want, once you are connect to the pi, you can click on the little icon to the left of the address bar and drag it to the desktop to create a permanent link to "\retropie" (or once you see it in network again, click and drag to make a desktop shortcut). That might save future hassles.
EDIT: You are welcome for the help. My programming skills aren't good enough to contribute to Retropie, but I have years of tech support experience, so I just try to help out where I can.