[U-Boot] help command not working in u-boot

Hi

I have added a new command in the "test_cmd" u-boot. after adding test_cmd , help command and many of the other commands are not working. help command gives Unknown command 'help' - try 'help'. tftp gives Unknown command 'tftp' - try 'help'. The command i have added is working fine. I have seen the u-boot.map file, in this file all the commands are defined. Can you please tell me what may be wrong.

Thanks Rupesh