I just had this dumb error where magicJack simply stopped dialing or recognoising my phone's tones so I just wanted to do this little post about the problem. This works for Windows 7 and probably for other Windows versions.
The simptoms are:
1. You dial a number and magicJack just continues giving you the dial tone.
2. If you open the magicJack application window and dial with the phone, you'll see it doesn't registers the key presses from the phone.
If you, someone or something has changed any sound configuration recently, then maybe it changed something it shouldn't.
1. Press the "Start" button.
2. Click on "Control Panel".
3. Click on "Sound".
4. Click on the "Recording" tab.
5. Right click inside the window and check "Show Disabled Devices" and "Show Disconnected Devices".
6. Right click "USB Internet Phone by TigerJet" and click on "Enable".
7. Click on "Properties", "Levels" tab and check that the sound is enabled and at a right level (not too low).