Happy (oh well) to hear someone with the same problem!
Recently bought an HP LaserJet P1505 (which according to the manual is essentially the same printer as the P1000 series) and downloaded the latest driver, installed it without problems, and even printed the test page, which worked fine.
The problem then starts when printing from any program at all: as you say, Stork, everything comes out horizontally elongated, with everything printing at least 400% too wide, resulting in most of the content ending up outside the paper (and the content staying inside being extended and ugly and only the leftmost part of the page).
(Too add some further confusion, I'd say there's also a second level of the problem: Things that should still fit on the page don't always print after all.
I think this is because the *bounding box* of every object is interpreted correctly, it's just the *graphic content* such as images and characters that are drawn out. Which means that even though with its faulty width a certain text should keep going past the edge, it might get cut off mid page because that's where it should end had its proportions been kept intact...)
Doing some research, I'm guessing the reason the Test Page prints correctly is because it doesn't actually use the HP driver, but some generic CUPS driver residing on the system (please correct me if I'm wrong here).
However, hoping to find a CUPS driver on the web, it seems the P1000/P1500 series aren't supported by CUPS (again, nothing would make me happier than if I'm wrong...)
Does this make sense to anyone? Anyone knows how to solve this?