A different Mac problem.
I had BBC Iplayer Desktop working well on my MacBook Pro, including the thing where it downloads programmes that I wanted to watch rather than streaming them. And then it completely stopped working. I got the "unexpectedly quit" message and that has been the end of it. I went through the uninstall, and reinstall process, including uninstalling Adobe Air (which is the core of the iplayer system as I understand it), and still I only get the "unexpectedly quit" message.
I have OSX Lion installed, as it was when I first downloaded desktop about two weeks ago, and I haven't changed anything about the os, or the configuration since then so am at rather a loss to understand the problem or correct it. Any suggestions will be welcomed! the only explanation that I can think of is that (there might have been) an update to Adobe Air which Iplayer desktop and OSX Lion are not ready for in some way.