I'm having the exact problem you describe in the Netflix channel but also in the ROKU Channel Store. The commands work perfectly in other channels otherwise.
If you press the arrow keys many times in a row the selection may move once.
Context:
I'm sending the commands via the Philips Pronto 9400.
This is assigned to my DOWN arrow key.
keypress2("Down");
This function is active when the arrow keys are available.
function keypress2(key) {
var url = CF.widget("aURL","PARAMETERS").label;
var timeout = CF.widget("aTIMEOUT","PARAMETERS").label;
var socket = new TCPSocket(true);
socket.connect(url, 8060, timeout);
socket.write("POST /keypress/"+key+" HTTP/1.1\r\n\r\n");
socket.close();
