If you are having any issues with deployments while mixing 450i Access Points and 450 Subscriber Modules, there are a couple of things to keep in mind.
The complete notes are found in the software release notes for R14.1.1 , but may be worth pointing out here.
If you're using the same software release on both the AP and SMs (which is always highly recommended), there is no need for any special settings.
If, however, there is a need or desire to run older software on your SMs, you may need to enable "PMP 450/430 Legacy Mode" on the AP.
This setting can be found in the device GUI under Configuration > Radio > Advanced.
When this is enabled, it will allow SMs to properly register.
With PMP 450/430 Legacy Mode set to Disabled, the network SMs must be
configured with the following software:
450 Series: 13.3 or greater
430 Series: 13.4.1 or greater