With the PS3, any remote command sent to it while it is in standby will cause it to power on. We chose "Clear" as a command because it is generally harmless but it accomplishes what we need: powering on the PS3. With the power sensing cable installed, the PS3IR-1000 will only send this command to the PS3 if it detects that the PS3 is in standby mode.
Please test the following, with your current configuration: Power on the PS3 manually or by using a controller. Scroll left and right a few times using your remote or the software utility. The PS3 should react to all commands sent. Unplug the Power Sensing cable from either the PS3 or the device. The status LED on the PS3IR-1000 should still be lit. Try sending some scroll commands (up, down, left or right) to your PS3 using either your remote or the software utility. The PS3 should not react to any of the commands. Report the results.