It seems that your Slingbox stopped working after the last software update.
First, the software update has nothing to do with the remote control issue. Keep in mind that every update is intended to improve the Slingbox functionality.
This issue might be related to the IR Blasters positioning. With this in mind, I recommend you to check the following link in order to apply some troubleshooting steps that might help you to fix this issue:
Hope this helps!