This is using Processing 1.0.1, with the built in video & OpenGL libraries.

Trying to allocate a Capture device while using the OpenGL renderer will
cause setup() to hang indefinitely, and the app will just show a blank
window until force-quit (it doesn't beachball, however–just won't quit
using the normal command). Capture works fine with the P3D renderer, which
leads me to believe it's an issue with the OpenGL renderer.

Smallest sketch to reproduce:
import processing.video.*;
import processing.opengl.*;

Capture video;

void setup() {
size(320, 240, OPENGL);

video = new Capture(this, 320, 240, 24);
}

No error shows up in the console.

I'm running Mac OS X 10.5.5 on a Core 2 Duo Macbook Pro.

See the note on the "known problems" page:
http://processing.org/reference/troubleshooting/#known

*** This bug has been marked as a duplicate of 882 ***