I'm having a really strange issue with data changing while a script is running even though the field isn't being set anywhere.
It's a basic invoice with line items. The script loops over the portal rows and reduces the amount in stock on the related products by the amount in the line item quantity.
Every once in a while, maybe one out of a thousand line items, the quantity on the line item will change to a different number. There is no 'set field' step in the script that references the quantity field, and it's just defined as a plain number field with no auto enter options enabled.
As weird as this sounds, sometimes it seems like the data might be "leaking" from another field... For example, if a product is a 24 pack of soda, sometimes the quantity will become '24', which is the value in the unit count field, but that field isn't even mentioned in the script. The unit count is just part of a concatenated calc field to create a product description display.
I've never been able to reproduce this in testing, but it happens about once a week to random users.