Hi,
If you acquired the asset in the special period for the FY 2011 asset acquisition value should display 2011 and depreciation will post in to 12 period in the plan values, and check the depreciation start date in the asset master data.
Please check the depreciation key settings and method using for depreciation calculation.
If possible please attach the screen shot for better understanding of the asset.
Thanks & Regards
Srinu
SAP Practice