Here in Europe Pentax has stopped selling the 645 because of environmental regulations. Too much solder or something silly.
Hans
As I understood it, the problem had to do with ROHS (Reduction Of Hazardous Substances) and there being lead incorporated in the soldering and lead tinning process for the camera's circuit boards. In some cases, the boards can be redesigned to eliminate the lead but it was either too expensive relative to expected sales or impossible due to lack of alternate components. Or both.
Should have been exempted, nobody throws away a camera!
They just circulate on eBay!