Index: trunk/grails-app/services/TaskService.groovy
===================================================================
--- trunk/grails-app/services/TaskService.groovy	(revision 812)
+++ trunk/grails-app/services/TaskService.groovy	(revision 816)
@@ -415,4 +415,7 @@
             result.taskInstance.properties = params
 
+            if(result.taskInstance.taskProcedureRevision?.maintenanceActions && result.taskInstance.isDirty('primaryAsset'))
+                return fail(field:'primaryAsset', code:"tast.operationNotPermittedToChangeAssetWithMaintenanceActions")
+
             if(result.taskInstance.hasErrors() || !result.taskInstance.save())
                 return fail(code:"default.update.failure")