I have a USB FM radio device. When you plug it in, a device file shows up under the /dev directory (e.g. /dev/dsp1). I opened this file with VLC using the Video4Linux device capture option. It played the file and I could actually hear FM radio.
After a few minutes, I closed VLC and I unplugged the device. When I tried it the next day, it stopped working: VLC can still play the file, however all you hear is static.
I tried it on another Linux machine and same thing happened: first time it played just fine, and after I restarted VLC, it stopped working.

What the heck is going on? I'm going crazy over this thing. What can I do?