When I switched my desktop Linux box to Ubuntu recently, I was able to get everything working relatively easily except for one thing: For some reason, I couldn’t stream MP3s from my mp3act server. The playlists would download properly, but nothing would play: xmms would just ignore everything in the playlists. Well, today I finally tracked the problem down, and it turned out to have nothing to do with Ubuntu. The culprit was my web proxy configuration. I run the Privoxy ad-blocking software (ObPlug: Privoxy really makes the web a much more pleasant experience). Now, I used to run a local Privoxy on each of my Linux boxes. But when I installed Ubuntu, I elected not to run Privoxy on the Ubuntu box. Instead, I configured Firefox to proxy through the Privoxy running on my server. That way, I only have to maintain one Privoxy installation. That works fine, but it does make all of my web traffic appear to come from the server rather than the desktop. And therein lies the problem. When mp3act generates a playlist, the URLs for the MP3 streams are all keyed to the IP address that requested the playlist. When xmms requests the stream, it doesn’t go through the proxy, so the requests come directly from the desktop, and the IPs don’t match. So, mp3act refuses to serve the file.

Solution: When talking to the mp3act server, use a direct connection and don’t go through the proxy. In Firefox, this is configured under Edit->Preferences->General->Connection_Settings. Once I made that change, everything worked fine.

Very very happy to have this working again!