Sheesh... The N900 loads a small portion of the OS if the phone is off when the user connects it to the charger to supervise the charging. When disconnected, the N900 unloads the OS and powers off. If stavros tries to boot the phone at the same time, it fails.
You have to wait ~10 seconds after pulling the plug before you start the phone. Or better, start the phone, and then unplug it.