I've got a battery question about my fiance's O2 XDAII (running Pocket Windows 2003). She said they other day that the main battery went flat and she lost everything in it. Which is odd because the backup battery was fully charged.

Now she also said she had removed the SIM card momentarily, which IIRC requires *removing* the battery, and that she'd done that without ill-effect before. Logic suggests this shouldn't be a problem, however, because extra batteries are easy to get - the cradle even has a slot for charging an extra battery.

Does anyone have any idea what went wrong?

(For the record, my own two portable devices both functioned different WRT batteries and backup-ness: my Newton has a capacitor that it charges off the batteries but most of its storage is actually flash; my Visor has a rechargable battery that you can't remove but it's battery life is very good.)

Wade.