There is info in zabbix_server.log:

1296:20111126:134608.041 Can not link template 'Template H': Template with application [core procs] already linked to the host
1296:20111126:134608.114 Can not link template 'Template H': Template with application [core procs] already linked to the host
1296:20111126:134608.186 Can not link template 'Template H': Template with application [core procs] already linked to the host

Information is insufficient to resolve issue in our zabbix environment. There are hundreds hosts linked to 'Temaplate H' and with a few of them there is something wrong with application.

It would be great to get a little more info in zabbix log (default DebugLevel=3)