For Auto-Discovery Rules with multiple Discovery Checks, Discovery Actions only allow the first Discovery Check.

• First create an Auto-Discovery Rule with 2 or more Discovery Checks.
• Then try to create a Discovery Action, with a Condition based on the second Discovery Check.
• Can't select second Discovery Check. Only the first is listed in the popup menu.
• This is a bug in 2.0; version 1.8 had all Discovery Checks available for selection.

Confirmed in http://www.zabbix.com/forum/showthread.php?p=98856