Hi,
Please check your user group dependency and go through the below sap help.
http://help.sap.com/saphelp_46c/helpdata/en/7e/5e03c24a1611d1894c0000e829fbbd/content.htm
http://help.sap.com/saphelp_erp60_sp/helpdata/en/48/35c6304abf11d18a0f0000e816ae6e/content.htm
Regards,
Dora