I am using Firmware 4.3.26, UI 4.2.30. I was not aware you had to or know how to upgrade the UI. I have always use the automatic upgrade option.
I have three ISY's at different locations, work, home, and weekend home. I have added numerous 4 scene and 8 scene mini remotes at all three locations without a problem, including another 8 button at this location. I have tried clearing the Java cache, done a factory reset on the remote, tried restore device, and every think else I could think of. I am beginning to think that I have a defective unit, but it is strange that it shows the light bulb icon and can be added to the scene as a responder. When I press a key, the status does change from on to off, but does not change the scene.