XBMC no longer able to stream media, invalid computer name message.

I've been streaming via my XBMC installed Xbox for years now, but about 2 weeks ago began doing so wirelessly using

It went ok for the most part, although every so often I'd have to reset my router for some reason to make them connect correctly.

Now though, I try and stream, and I either receive the message "invalid computer name" or a "can't connect to server" message, followed by a never ending "working..." message. Nothing else has changed in the meantime. When I press the button on my router to sync the 2 devices, occasionally I can access my media for 30 seconds or so, before I am cut off with the "invalid computer name" message.

If anyone could offer me any guidance on how to get things working again, it would be greatly appreciated.