We got this question on support call a couple times recently. The client was seeing decimals and commas out of place. The employees all swore they were entering the data accurately, but when the boss viewed it, the number were way bigger than they should have been.
The issue was that one of the employee’s preferences were set incorrectly. The digit grouping separator was set to a period when it should be a comma. The comma is the default so I am not sure how it was changed — the period looks a lot like a comma if your eyes are weak.
I hope that helps someone.