So much for firmware upgrades: there are none for the Yammie (outside the US), and when I upgraded the PS3 to 2.42, it hung after the restart. Apparently 2.41-2 were to fix a problem just like this that occurred with 2.40: I hadn't done the 2.40 upgrade, so the gods decided to bite me on 2.42. Off to Sony support. Sigh. At least it's still under warranty.

Regards,
David