This is my second experience:
- Running GS for 1-2 hours again (I was having trouble modem connecting to server). Being very careful to press a button only once every 2 seconds.
- Becomes "Slow Remote" at "Channels you Receive".
- Again, CPU quite hot but PSU heatsink even hotter.
- I rebooted (into GS mode). Only got in about 3 button presses before became "Slow Remote" again.
- I rebooted (into GS mode). Became "Slow Remote" immediately.

So this time, I was not overusing the remote, but I got exactly the same symptoms...