Recording telephone calls is no longer working

I used to record telephone calls with a device similar to the one below.

I’m now not able to get it to work. When it did work, I would not here the telephone over the speakers when recording and turning the phone on to get a dial tone, but the wave signal on Audacity would fluctuate with the volume of the speaker. Now, I hear the telephone over the speakers, and the wave signal on Audacity is a flat line and nothing is being recorded. I believe I connected the device properly to my PC and telephone, so I’m assuming there is a setting on Audacity that needs to be changed. Any ideas? Thanks.

[u]This Tutorial[/u] shows you how to select the input you want to record. If you have a laptop, make sure you’ve selected the external mic, and not the built-in mic.

Windows has separate recording & playback mixers, so you don’t always record exactly what you hear from the computer speakers. (And FYI - The recording mixer isn’t a true “mixer” since you can only select one input at a time for recording.)