Jenda's repository appears to be down at the moment. This caused ppm to "sit and wait" for an awfully long time, with no feedback for several minutes, until it finally failed for me.

So, obvious point, but you might want to mention that it's worth checking a repository with your web browser, or pinging it, before adding it, since ppm is so slow for this.

UPDATE: So, I wrote a Script to update your PPM Repositories