Those pops are really unnerving. But you can only point the finger when the problem turns up to every user on different platforms.
I had a similar experience with 8Dio's wonderful Upright Piano. I downloaded and installed the normal way and found out pops at a specific mic position happening 100% predictable at some transitions of notes. I felt really upset. I was planning to get things straight. I just held myself from sending a furious mail, because you never know..
So I wrote a polite mail sending a soundcloud link with the problem clearly stated, and I was replied quickly, politely and friendly. However they weren't able to reproduce my pops at their end of the line on their system.
So after a while I received the suggestion to re-install the librabry. And that was it. Pops gone. Everybody happy. Bad installation. That just happens. Is it my disk reading/writing errors? Copy errors? Unzip errors? I have no idea.