Just tried this for the first time, and the current update is working great at time of posting.
The biggest irony is that it's better than the AIR based BBC iPlayer, but not in the DRM -stripping way you might think;
The iPlayer application prioritises it's streaming video way above the downloads, in short, this means that your hour long program can takes hours to download. However, this app gets it's files directly via the Stream, which basically means you can get it as fast as your DSL will let you.
In short, even if you don't have issues with DRM, this little program destroys the official iPlayer application on multiple levels, there is really no reason not to use this instead.