XBMC on Ubuntu - Says file not available that VLC will play on same Ubuntu pc

OK... I am officially STUPID.

In XBMC for Windows or Android, when you create a video source, you can simply type "smb://ip_address/share" and it will work. But not true in Linux.

In Linux, you must first go to Videos, then Files, then Add Videos, then click Browse, then (and this is really important) scroll down until you see Add Network Location, then follow through with that to create a new Network Location (e.g. smb://ip_address/share).

After creating the new Network Location, you can then select the new Network Location and complete the process of creating a new video source.

I have had to follow that procedure on one machine, but in general I don't have to do that on Linux. All very odd.