How do I install a SensaSwitch on a 3-way circuit?

I recently purchased a SensaSwitch, Manual-ON / Timed-OFF (PDF of instructions) and I cannot install it in such a way that it performs as I desire. I have a switch at the top of my basement stairs and a second by the exit, both switches control the entirety of the basement lights.

I want to install a switch that will turn off after x minutes have passed that way when I leave through the basement the lights will automatically switch off without the need of using the bottom switch. I have been able to wire the top switch to perform this function. After dark, if a person enters through the basement he must turn on the switch by the door for the lights to come on. With the configuration that auto-turns-off, the bottom switch becomes completely useless. Is there a way to wire these two switches so that they perform as desired?

Here is a diagram of the circuit:

In the Top Wire Box (one gang) are five wires; because of the age of the wires it is difficult to tell the colours, mostly the wires look black except for a yellow and a red wire which are joined. From one port come a wire which is black with bits of white throughout, a wire which is black, and a wire which is red. From the other port is a wire which is yellow and a wire which is black.

I have tried a multitude of connections to the Timer Switch, but I have not unbundled the red and yellow wires (and I hope I won’t need to). The timer switch has four ports: “3-Way,” “White,” “Hot,” and “1-Pole.” The configuration which seems to work is: Black & White Wire and Black Wire in “1-Pole,” Black(marked hot) in “Hot.” I have managed to make it function with a different wiring but I did not record it (the Black(marked hot) was in “Hot”).

This Timer Switch comes equipped with LEDs which should illuminate when the switch is off, but all I have yet seen them do is flicker randomly. The instructions say that a Neutral Wire is necessary for the LEDs to work properly. I do not need the LEDs to turn on if it is possible to make this work otherwise, at the hardware store the sample did not have functioning LEDs.

Please advise. I am very eager to make this work and am willing to try virtually every combination (in fact, I’ve already tried a great many unsuccessful configurations).