Uneven playback volumes of some keys in soft instrument.

I can reproduce by dragging the same audio file - file format doesn't matter - into F#2, G2 and A2. When I play these notes using musical typing the audio file plays back at noticeably different volumes - G2 is always much softer. All effects are off. Messing with velocity sensitivity doesn't change behavior. Neither does triggering from MIDI with identical velocities. Can anybody else reproduce this?