Hi,
It would also be interesting to know the last time the extension was updated; besides that expecting unmaintained extensions to work on a new major release might not be plausible, the extension is likely not be adapted to any change if it is unmaintained, no matter how popular it is (example: the most popular, Oracle PDF Import Extension, Downloads: Week: 12,706, unmaintained since Dec. 2010, seems to be broken - according to the first three comments).
within the last days I've installed the Windows variant of the PDF Import Extension several times on different systems (Win7, Win8) and all of those installations worked like a charm.
Kind regards, Joost