Every time I get a new gadget, it comes with a USB to mini USB cable, and the instructions say to only use the supplied cable, so I have. Is there any harm to be done by using say, the Panasonic camera cable for the Sony reader? The only obvious difference is in the hard barrel shaped fitting.
Perhaps I've been lucky but I always use the first one that comes to hand. Never had a problem so I would say there is no difference. (manufacturers may say otherwise of course - thinking of overpriced gold-plated cables !!)