iDisk: today it simply doesn't work at all

Yesterday I complained that my iDisk was slow. Today, it simply doesn't work at all. This dialog has been on-screen, unchanged, for 15 minutes:

All I was trying to do was make a local copy of a folder on the iDisk.

Worse, the dialog wouldn't leave when I hit the small ‘x’-button which claims to ‘Stop copying’. So I relaunched the Finder, which has now completely crashed. Awesome.