dc_shell-t initialization error

cmd-013

When I invoked dc_shell-t, I got the following messages:

Version V-2004.06-SP2-6 for linux -- Feb 18, 2005
Copyright (c) 1988-2004 by Synopsys, Inc.
ALL RIGHTS RESERVED

This program is proprietary and confidential information of Synopsys, Inc.
and may be used and disclosed only as authorized in a license agreement
controlling such use and disclosure.

Initializing...
Error: Cannot create procedure named 'group_variable' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'group_variable' cannot be modified. (CMD-051)
Error: ::group_variable
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'print_variable_group' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'print_variable_group' cannot be modified. (CMD-051)
Error: :rint_variable_group
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_verilog' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_verilog' cannot be modified. (CMD-051)
Error: ::read_verilog
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_sverilog' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_sverilog' cannot be modified. (CMD-051)
Error: ::read_sverilog
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_vhdl' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_vhdl' cannot be modified. (CMD-051)
Error: ::read_vhdl
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_db' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_db' cannot be modified. (CMD-051)
Error: ::read_db
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_edif' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_edif' cannot be modified. (CMD-051)
Error: ::read_edif
Use error_info for more info. (CMD-013)
Error: Cannot create procedure named 'read_ddc' - existing command
Use error_info for more info. (CMD-013)
Error: Procedure 'read_ddc' cannot be modified. (CMD-051)
Error: ::read_ddc
Use error_info for more info. (CMD-013)
dc_shell-t>

I found these errors were caused by two commands in .synopsys_dc.setup:
source $synopsys_root/auxx/syn/.dc_common_procs.tcl
source $synopsys_root/auxx/syn/.dc_procs.tcl

But the .synopsys_dc.setup file in my working direcory is the original one which synopsys provided. How can I avoid these error messages?