I am trying to drop tempdb tables using one stored procedure. I am getting following error message:

Msg 3701, Level 11, State 1
Server 'whq_dev1', Procedure 'sy_droptmp', Line 26
Cannot drop the table 'tempdb..mytable', because it doesn't exist in the system

The table mytable is present in the tempdb.
When I am trying to drop this table at command prompt (using drop table tablename) it works fine.

Any ideas why is this error message?