Regarding the scan script; if I use any subtract other than one, it always gets a false positive.
I've used subtract values from 16 up to in the thousands and always get a wrong result (false positive).
If you use a large subtraction number, the result shows up way out of the upper limit range.
Can you shed any wisdom as to why?
If in subtraction you used 16 to create the db in the search script you should do the same, it is not that they are false positives, it is that the pk calculation is deconfigured if it does not have the correct values.