State Amended Tax Return

I filed our taxed at the beginning of February.  We received a Federal return but owed State taxes of $458.  Fast forward to this week and I get a letter from my company stating the payroll software had overstated my taxable wages on my state portion of the W-2 by $900.  When I filed the amendment it showed zero was owed or due, so do we still owe the original $458? Shouldn't that have gone down with the amended return?