I had the same problem with the roku simple remote. The remote had to be 12 inches from the roku to work.
I opened the remote found there is a single IR LED being driven with 3 volts. The forward voltage of the LED is only 1.4V max, thus it is being over driven and failing. I replaced the LED and all it is working again.
The LED circuit has a 0 ohm resistor in it, it needs maybe 25 ohms to limit to under the 100 ma that most LED allow.
A pretty bonehead move by roku.
