I discovered a strange bug while trying to move duplicated filter values into the global zone in one of my SoundFonts: occasionally, pasted Hz values would be different than their source. After some investigation, I discovered that this affected typed values as well.
How to reproduce:
1. In the "Filter, cutoff (Hz)" field of an instrument zone, type 5000 and press enter. Polyphone will change the value to 4998. This alone is not concerning, since not every numerical value is available for filter cutoff, and some values between 0 and 20,000 must be skipped. However, it gets stranger...
2. Now we know that 4998 is a valid value for filter cutoff, so delete 4998 (outside of text edit mode--this is important) and type 4998 followed by enter. The number changes to 4995.
3. Select the field containing 4995 outside of text edit mode, copy (Ctrl-C) and the clear the cell by pressing delete. Then, paste (Ctrl-V). The pasted number shows 4993.
This behavior also happens with the fields for "Mod LFO freq (Hz)" and "Vib LFO freq (Hz)". You can repeat the reproduction steps in these fields using the numbers 10.003 and 10.002 instead of 5000 and 4998 respectively.
