SRW.USER_EXIT - FND FORMAT_CURRENCY returns different values for the same set of parameters passed

We have a code in a custom report where we are trying to format an amount and display in the output of the report. We are passing the same parameters in each scenario but the formatted value is returned differently in each case.

The following code is used -

SRW.USER_EXIT('FND FORMAT_CURRENCY 

                CODE=":C_CURRENCY_CODE"

                DISPLAY_WIDTH="12"

                AMOUNT=":C_PS_DISCOUNT_AMT"

                DISPLAY=":C_PS_DISCOUNT_AMT_DISP"

                MINIMUM_PRECISION=0');

Case 1 : For Operating unit 1

---------------------------------------------

MSG-00001: :C_PS_DISCOUNT_AMT - 0 :C_CURRENCY_CODE - USD

MSG-00002: :C_PS_DISCOUNT_AMT_DISP -         0.00

MSG-00003: V_PS_DISCOUNT_AMT_LN - 1