Roomba Black Rug Problem

As we all know, I love my Roomba, but we got in some black entrance carpets from Costco before Christmas. Wouldn't you know, but the sucker thinks it's falling off a cliff as soon as it hits it! It has 4 of these IR cliff sensors, so it doesn't fall down the stairs, but black rugs confuse it greatly.

After much search, I found a solution. Get clear hockey tape, take a 4 inch piece, roll it loosely as a half-inch flat cylinder several times, until it looks like a piece of murky glass. This is important, since you want the IR to reflect. Then tape each of these elements, over the sensor. Voila! Black carpets are clean! Block the stairs some other way. :)