Hi Steve. I canot duplicate this problem. Left / Right arrow keys tune 1 kHz. If I hold control key, it does a seek to the next active signal. If I hold ALT key, it changes the Keyer speed.
Maybe there is something strange about your keyboard. Try playing with the NumLock key. Maybe sticky keys are turned on for your Windows. Try both sets of arrow keys. Maybe you are holding down both control and ALT together.