What do you mean when you say "did not work reliably"? I am running it right now (gotta love the blinking lights ) and it seems to work fine (wired keyboard, didn't touch a line of code within the script so it is as-is from the net). Very handy for me, I didn't even have a mobo LCD to show HDD usage.
I compared the HD light on my computer and the Scroll Lock LED. They rarely matched. In fact, the scroll lock LED would blink even when there wasn't any indicated activity from the computer.
I am using a wired Logitec keyboard.