Nope, PS3 Media Server didn't do it either. I can see them all in the list of available sources, but none of them return any content.
Ah, UR, and the "official XBMC Remote" from Team XBMC seem to connect via http. Got EVERYTHING turned on in that section though.
If it's any help, then the Channels don't seem to work either. I added the SHOUTcast Channel yesterday (which only turned up just now) and can't get anything from there either.
One thing I haven't tried yet is using Skifta over a mobile connection.
I'll take a look at logging later