Data Type for Field is Whole Number (integer)
Client enters number starting with zero. On moving to next field, zero is removed from the number!
Open the text box properties in the design view of the form.
Select Format, next to the Data Type (which should be Whole Number (integer))
Change the Format from Number to None (display XML value)
Now enter a number staring with Zero and you will notice that when moving to the next field, zero is not removed from the number.