Apple has released the Time Capsule and AirPort Extreme Base Station Firmware Update 7.5.1 that provides several fixes that many users have been complaining about such as:
• Not importing all settings when importing a configuration.
• Not propagating MAC address control lists when using an extended network.
You can learn more about the firmware update and how to install here. Of course the update will be available via Software Update. However, its recommended that you install the latest Airport Utility 5.5.1 beforehand. You can grab Airport Utility 5.5.1 for Mac or Windows here.
[via Software Update]