I agree! When I called the MB dealership near me in the UK I expected the unit to be a special order and was surprised when they told me they always keep a good stock on the shelf as they are always replacing failed units on a regular basis.

When I replaced the batteries in mine I attached a multimeter to the battery pack and monitored it for a few hours to see if there was any form of charge / discharge cycle going on. Over the 6 hours I monitored I didn't notice any discharge at all. So fried nicads are a distinct possibility.