On OSX 10.9, Ableton live 64bit 9.1 and Kaivo VST 1.0.
Really strange behaviour here. If I load a custom sample, 8 seconds long, of a sawtooth wave just playing a static 440Hz. I set pitch at 0, rate at 7, X-pos in the very beginning of the sample, wrap off, and play, everything is fine. If I then play a low C, everything is still fine, until I start to move the X-pos slider. When the slider passes somewhere approx half way, the note suddenly changes to one semitone up. Playing A# and doing the same, makes the note jump one semitone down instead. Whaaat?
In fact, with the X slider all the way to the right, pitch track is seeeriously off. In the lower registers, it's like it quantizes to four pitches per octave or so, and further up the scale it's just basically rather out of tune.
The relationship between pitch, rate and your source sound in the granulator is kind of complex. Please check out the manual section on pitch vs. rate (pg. 13)
In general, you have to connect both the pitch from the KEY modules to both the pitch and rate inputs of the granulator to play in tune. And, the patcher output dials (sometimes called attenuverters around here) have to be at their default (double-click) settings.
Also if you have an oscillator sound without "wrap" on, you will get weird effects near the end.
If after some exploration you think you have really identified a bug, you can send me the patch w / audio file to support @ madronalabs.