packages addupdate on redhat

consider this promise:

packages:
"libyaml"
package_policy => "addupdate",
package_method => yum_rpm,
handle => "package_libyaml_add";

state before running:

[root@ip-10-112-34-210 inputs]# rpm -qa | grep libyaml
libyaml-0.1.5-1.el6.x86_64

[root@ip-10-112-34-210 inputs]# yum update libyaml
Loaded plugins: security
rightscale-epel | 951 B 00:00
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package libyaml.x86_64 0:0.1.5-1.el6 will be updated
---> Package libyaml.x86_64 0:0.1.6-1.el6 will be an update
--> Finished Dependency Resolution

Dependencies Resolved

========================================================================================================================
Package Arch Version Repository Size
========================================================================================================================
Updating:
libyaml x86_64 0.1.6-1.el6 epel 52 k

Transaction Summary
========================================================================================================================
Upgrade 1 Package(s)

now run agent, relevant verbose log output:

2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Comparing [available] package (libyaml,0.1.5-1.el6,x86_64) to [==] with given (libyaml,,) [name,version,arch]
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Matched [available] name 'libyaml'
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Matched [available] wildcard arch '*'
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Matched [available] wildcard version '*'
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: PackageMatch: package comparison for [available] libyaml was decisive: MATCH
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: CheckPackageState: Available package match for (libyaml,,) [name,version,arch] was decisive: MATCH
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Additional promise info: handle 'gjm_package_libyaml_add' version 'CFEngine Promises.cf 3.6.0' source path '/var/cfengine/inputs/gjm.cf' at line 127
2014-05-02T12:53:36+0000 verbose: /default/gjm/packages/'libyaml'[0]: Package 'libyaml' already installed and matches criteria

end result is that the package is not updated when it should be.