Finally got this to work with stock AT&T Tilt
Thanks to everyone involved.
Vito Audio Notes was tricky to figure out. I uninstalled and reinstalled it several times before I got the settings right.
Move the yellow equalizer all the way to the left when recording. Set the microphone gain to high.
If you move the yellow equalizer all the way to the right, it will only record very loud sounds, which doesn't work for recording phone calls. If you set the microphone gain to low, the recording will be hard to hear when you play it back. You'll have to hold the speaker up to your ear.