Zoneminder uses shared memory for accessing video devices. You may find that after changing the resolution from 320x240 to 640x480 (NTSC) the camera does work in Zoneminder. This is most likely a shared memory problem and is easily fixed. You may see these errors in the Zoneminder debugging logs: Can't shmget: Invalid argument See the Zoneminder FAQ or this page for more information on how to fix this problem.