We find this from time to time. It appears due to a poor path to the server from the streaming source. We are running Icecast2-KH servers and find it particularly when coming in via the Shoutcast v1-style DJ-account login, where you basically take over the AutoDJ mount point and the AutoDJ is silently whirring away in the background.
We use a hardware streaming source (a DEVA DB91-TX) and if it gets thrown off, it will try to get right back in with no delays and keeps trying till it succeeds, so you generally get a very short blip of AutoDJ content (just enough to mess up the metadata!) before it powers back in. As distinct from, say, Nicecast, which is configurable to make a few rapid tries when it gets thrown off and then wait for a bit before trying again.
When I get events of this type I run up PingPlotter and look at what the path's doing, and there are generally hiccups happening somewhere down the line.
So... unless there is something weird happening with your streaming source client, it's something going on (or off) between you and the server, and c'est la vie.