snmp set gives error

I installed ucd-snmp plus ucd-snmp-utils, set up my snmpd.conf and started the snmpd. Tested it with a few things like snmpwalk and snmpget and snmptranslate, all worked fine. Then when I tried to do an snmpset I got an error. Here the call: snmpset <system name> <rw community> sysContact.0 s <an email address> I get an error like: Error in packer. Reason: (noSuchName) There is no such variable name in this MIB. I can do a get like: snmpget <system name> <rw community> sysContact.0 which returns: system.sysContact.0 = <email address as defined in config> Anyone know or understand what this means?