change column name of a temporary table SQL SERVER 2008

I have problems when renaming columns in a temporary table are several I have executed this example script and I get the following error

  

/ Faulty Rename / EXEC sp_rename
  'dbo.AllocationDetails. [Conversion_Fee_Per_Share]',
  '[Conversion_Fee]', 'COLUMN'

     

/ Fixed Rename / EXEC sp_rename
  'dbo.AllocationDetails. [[Conversion_Fee]]]', 'Conversion_Fee',
  'COLUMN'

     

Error: Either the parameter @objname is ambiguous or the claimed   @objtype (COLUMN) is wrong. SQLState: S0001 ErrorCode: 15248