If I follow the directions on p. 3 and p. 6 of the 4684 Instructions referred to above - then I add the Standard Deduction amount (in my case $27,300) at line 16 of Sched A.  Well, then ProSeries added all the normal itemized deductions + the casualty loss amount (transferred in from 4684) + the Standard Deduction amount added on line 16 to come up with an inflated itemized deduction.  This would be great!  Could I just tell the IRS that my ProSeries program made the booboo?