I was using the sifter item (diamond) and noticed it had a -1/127 while on my server. So I decided to check what would happen if I had went to single player and used an iron one and it also goes into negative values.
I decided to go into a profile with just ex nihilo omnia to test if that would also occur or not. Tested and it does occur.
*Throwing sifter out doesn't make it disappear either.
*Also using Omnia version 1.1.4 and forge 2095