When typing a number longer then 16 digits in a form field who's security is set to "numbers" and then clicking out of the field, Acrobat auto changes the last few digits to random numbers. For instance, I was trying to type 12345678901234567890 into the "account number" field and when I tab/click out of that field to the next, it is changed to 12345678901234567168". Removing the security resolves the issue, but the client wants to only allow numbers to be entered into this field.