The UCD SNMP server is compiled without libwrap, the TCP wrapper library (which I have been using for a while). There is a comment in the .spec file that it doesn't work, but I added back (to both configure sections in the .spec file) a "--libwrap=-lwrap" and it works fine.
Compiled with libwrap in dist-6.0 ucd-snmp-3.5.3-4