@bjc Hello bjc, thanks for your report. We are certainly interested in fixing whatever problems if we can reproduce them. The Model 01 keyboard in our possession has the stock firmware. We have not upgraded it to any other version. When we tested it all the standard keys seemed to work. We will test again but it is odd that some keys work but not some others (e.g., forward slash which is a standard key). You are correct Boot protocol does not support media keys but how did you switch the keyboard to use Boot protocol? The BT-500 should support both so we will investigate why it stops working when the keyboard is in Boot.