Have you made any important change in the driver internals? The last firmware update has broken the OpenMAX transition from unloaded to idle. After 5 seconds of inactivity with the led turned on, I get an error: OMX_ErrorInsufficientResources.
Using the raspistill I also get an error:
mmal: mmal_vc_component_enable: failed to enable component: ENOSPC
mmal: camera component couldn't be enabled
mmal: main: Failed to create camera component
mmal: Failed to run camera app. Please check for firmware updates
OS: Arch linux