When selecting to shutdown vm's from the admi portal, it often doesn't work although, sometimes it does. These machines are all stateless and in the same pool, yet sometimes they will shutdown from the portal, most of the time they don't. here's what I see in engine.log when they don't shutdown. 

2014-05-19 18:17:42,477 INFO  [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (org.ovirt.thread.pool-6-thread-2) [4d427221] Correlation ID: 4d427221, Job ID: ce662a5c-9474-4406-90f5-e941e130b47d, Call Stack: null, Custom Event ID: -1, Message: VM shutdown initiated by Jeff.Clay on VM USAROVRTVZ-13 (Host: USARPAOVRTHOST02).

2014-05-19 18:22:45,333 INFO  [org.ovirt.engine.core.vdsbroker.VdsUpdateRunTimeInfo] (DefaultQuartzScheduler_Worker-53) VM USAROVRTVZ-13 67a51ec0-659d-4372-b4f1-85a56e6c0992 moved from PoweringDown --> Up

2014-05-19 18:22:45,381 INFO  [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (DefaultQuartzScheduler_Worker-53) Correlation ID: null, Call Stack: null, Custom Event ID: -1, Message: Shutdown of VM USAROVRTVZ-13 failed.