There are two bad samples in the downloadable Rain Piano (Kontakt Version). Notes A3 and A#3 have a bad click in the second to highest velocity dynamic. Not sure if this affects Giga version or not. Very noticable stuff. Anyone else getting this? Seems to happen in the all the various versions (soft, dynamic, etc.) so its in the samples.
This rings a bell - I think I've heard this in my Kontakt version, which was from a disk that was free as a promo with White Grand. I'll check it out tonight and post back. I have the Gigastudio version too and will see if it is in that one too.
For me it's G#1, A1, and A#1 on the top velocity layer - it goes "ping!" on the attack (think thumbtack on the hammer) when the others around it do not. There is similar behavior on the high velocities around the bottom notes, but those would be much less-used.
I really like this piano, but that is one sample I'd change. I might have a wack at it in Wavelab and see what I can do.