I'm starting to think there must have been a bad lot of them. There are a lot of threads lately about PT's dying and/or malfunctioning. Search and you'll see it's not limited to any vendor in particular. Makes you wonder.
There are so many different manufacturers making them it's hard to think of anything that would lead to all of them putting out bad PTs at the same time. So, I figure it's more likely to be a coincidence or a case of confirmation bias, than an actual sudden wave of bad PTs.
These things tend to go in cycles, and feed on themselves. One person starts a thread, others spring up, and suddenly it seems like everyone's getting bad ones. PTs are somewhat unreliable in general, and manuals expecially so. Like someone else pointed out in another thread, it's the nature of the chipset on the switch.