VLC not parsing audio files correctly

Question

I've had a good experience with VLC, but recently some weird things are happening with some audio files:

1. In the playlist, the time of the audio will jump around
2. If I skip around in the file too much (fast forward, rewind) it will either start in a random location earlier in the file or stop playing altogether (I have to play it again to start). If I skip forward or backwar just once or twice it won't mess up.
3. Sometimes if I start playing at a random location in the file it will jump back a ways, and then play at ~5x (accelerated speeds, sounds like chipmunks) until it reaches the location I originally selected.

This has never happened with video, only audio files from different sources. These are usually mp3's (I believe), and should be well encoded (by the author) and uncorrupted (from download or storage). What could be causing these symptoms?