Tax Depreciation - HY Depreciation Method adjusts depreciation in final MONTH of life, not final YEA

We have 5 yr MACRS HY assets that were placed in service 1/1/2010, that should have depreciation expense through half of 2015, the 6th year of the assets lives, in accordance with the HY convention rules.  Oracle fixed assets seems to see that the 60th month of the asset life is Dec 2014 and is adjusting the depreciation expense for that month to fully depreciate the remaining asset value.  This is happening for all assets in our tax books, placed in service the first month of any fiscal year.  How can we get the fixed asset system to allow the