After an OTA firmware upgrade, most devices won't work with the SBrick.
Some devices can connect, but the controls don't work, some devices don't even connect.
This is because Android won't refresh the list of services offered by the SBrick, and new firmwares tend to change that list. Using the old service list results in issuing wrong commands, because the phone only transmits the given servce's number (for the tech-savvy: the characteristic handle).
If the list changes, chances are the numbers will also change.
Turning the Bluetooth off and on again usually forces the phone to refresh the service (and service / characteristic / descriptor) list of the device.
Some devices won't refresh even after that. In this case, look for the "Bluetooth sharing" (or similar) application in the application manager, and clear cache and data, then force-stop the application (it will restart by itself). Do the same with the SBrick application too.
If that doesn't help either, try to restart the phone.
If your SBrick still doesn't work after the OTA, try to pair with the SBrick. WARNING: DO NOT unpair and SBrick with firmware version less than 4.4. Certain devices will not be able to pair again with an SBrick that was paired to that device before. If pairing is required for reliable operation (as we've experienced in certain cases), your phone will just stop working with that SBrick. Even factory resetting the phone won't help.
This is because older SBrick firmware stored a so-called bonding information for devices, and having such information interferes with pairing again in some situations.
Performing an OTA update on an SBricks clears bonding information, so if you've paired and then unpaired an SBrick with firmware version less than 4.4, you have to find an other device and perform an OTA update.
The 4.4 firmware operates SBrick in non-bondable mode, so it will not remember anything about being connected to a device, and pair/unpair is not a problem anymore.