FWIW (I know this is an old thread) my original pump just bounced off the frame one day.
I hadn't realised what had happened - other than I heard a noise - and had thought that perhaps I'd lost a rear light. But as that was still attached, I assumed I'd run over something. It wasn't till a lot later that I even realised it was missing.
I didn't buy another as I had issues with it anyway. The way it fitted always seemed to be upside down to me. With the handle at the bottom, it just always seemed to be full of water and was really rusty - despite being only something like 6 months old when I lost it.
I had a couple of old ones lying around, so I just grabbed one and now keep it in my rucksack. No idea whether it's HV or HP, it's more a "get some air in the tyre to get me home" pump.