Weird drools problem

[wespe]

security.drl contains:

rule ModifyMyself
  no-loop
when
  $perm: PermissionCheck(name == "userDetailHome", action == "update", granted == false)
  Principal($username: name)
then
  $perm.grant();
end

UserDetailHome is the following:

@Name("userDetailHome")
public class UserDetailHome extends EntityHome<UserDetail>
{
    @RequestParameter
    Long userId;

    @Override
    public Object getId()
    {
        if (userId == null)
        {
            return super.getId();
        }
        else
        {
            return userId;
        }
    }

    @Restrict("#{s:hasPermission('userDetailHome', 'update', userDetailHome.instance)}")
    @Override
        public String update() {
                return super.update();
        }

        @Override @Begin(join=true)
    public void create() {
        super.create();
    }

}

editUser.xhtml is like this:

<h:form id="editUserForm" enctype="multipart/form-data">

                        <rich:panel>
                                <f:facet name="header">Edit User</f:facet>

                                <s:validateAll>
                                        <div class="dialog"><h:panelGrid columns="3"
                                                rowClasses="prop" columnClasses="name,value,message">
                                                <h:outputLabel for="username">Username</h:outputLabel>
                                                <h:outputText id="username" value="#{userDet.username}"
                                                        required="true" />
                                                <h:message for="username"/>
                                                <h:outputLabel for="first">First Name</h:outputLabel>
                                                <h:inputText id="first" value="#{userDet.firstName}"
                                                        required="true" />
                                                <h:message for="first"/>
                                                <h:outputLabel for="last">Last Name</h:outputLabel>
                                                <h:inputText id="last" value="#{userDet.lastName}"
                                                        required="true" />
                                                <h:message for="last"/>
                                                <h:outputLabel for="email">Email address</h:outputLabel>
                                                <h:inputText id="email" value="#{userDet.email}"
                                                        required="true" />
                                                <h:message for="email"/>
                                                <h:outputLabel for="phone">Phone Number</h:outputLabel>
                                                <h:inputText id="phone" value="#{userDet.phone}"
                                                        required="false" />
                                                <h:message for="phone"/>
                                                <h:outputLabel for="image">Profile image / avatar</h:outputLabel>
                                                <s:fileUpload id="image" accept="image/png,image/gif,image/jpeg"
                                                                data="#{userDet.image}"
                                                                contentType="#{userDet.imageContentType}" />
                                                <h:message for="image"/>
                                        </h:panelGrid></div>
                                </s:validateAll>
                                <h:commandButton id="save" value="Save" action="#{userDetailHome.persist}"
                                        rendered="#{!userDetailHome.managed}"/>                                 
                                <h:commandButton id="update" value="Save" action="#{userDetailHome.update}"
                                        rendered="#{userDetailHome.managed}"/>

                        </rich:panel>

                </h:form>

finally, components.xml part:

        <drools:rule-base name="securityRules">
                <drools:rule-files>
                        <value>/security.drl</value>
                </drools:rule-files>
        </drools:rule-base>
        <security:rule-based-permission-resolver
                security-rules="#{securityRules}" />

I get:

Caused by: org.jboss.seam.security.AuthorizationException: Authorization check failed for expression [#{s:hasPermission('userDetailHome', 'update', userDetailHome.instance)}]

Than the entity gets updated!?!?!?!

And once again:

Caused by: org.jboss.seam.security.AuthorizationException: Authorization check failed for expression [#{s:hasPermission('userDetailHome', 'update', userDetailHome.instance)}]

Could someone please shed some light on this? I'm really feeling lost, though it seems so easy to implement..