Jan –
It’s definitely a problem. I had the standard battery on my HVX just from a flight from LAX to London to Nairobi in a Petrol Case very well packed and secured and the battery broke off the clips while in transit. It was very frustrating seeing as I began my trip to shoot African Wildlife with a broken camera and had to jerry-rig a two-sided velcro strap to hold the battery on.
In Bulgaria now shooting but will call Panasonic and my warranty company when I return and let people know the results.
Cheers,
Rob