And now, having installed Windows and played a small amount of Oblivion on it, we discover that there’s a bug in the firmware upgrade we installed to be able to run Bootcamp. Now every time the iMac wakes from sleep, the display shows nothing but a set of randomly coloured vertical lines. It has to be shut down remotely and left for a while before it will reset, if it does. Poo.
Fortunately, there exists a download from Apple to restore the original firmware. But so much for Windows, at least until that bug is fixed.