Nikon has issued firmware updates for the D4, D800 and D800E cameras to fix the lock-up issue, as well as other bug fixes.  Officially, the firmware update resolves the following issues.

Nikon D4 resolved issues:

• When a still image was captured while viewing existing images in playback mode, the monitor turned off, the memory card access lamp glowed steadily, and, in some rare cases, the camera ceased to respond to operations. This issue has been resolved.
• When network functions were used with certain settings applied, RAW images were also transferred when Network > Send file as was set to JPEG only. This issue has been resolved.
• When an option that utilized the main command dial was selected for Custom Setting f15: Playback zoom, and an image was zoomed in or out with playback with certain settings applied, shooting shutter speed, aperture, and exposure compensation settings were sometimes changed. This issue has been resolved.

Nikon D800 resolved issues:

• When a still image was captured while viewing existing images in playback mode, the monitor turned off, the memory card access lamp glowed steadily, and, in some rare cases, the camera ceased to respond to operations. This issue has been resolved.
• When the Wireless Transmitter WT-4 was used with certain settings applied, RAW images were also transferred when Wireless transmitter > Transfer settings > Send file as was set to JPEG only. This issue has been resolved.
• A dark shadow sometimes appeared at the bottom edge of images captured with Active D-Lighting set to any option other than Off with Image area set to 5:4 (30x24). This issue has been resolved.

Nikon D800E resolved issues:

• When a still image was captured while viewing existing images in playback mode, the monitor turned off, the memory card access lamp glowed steadily, and, in some rare cases, the camera ceased to respond to operations. This issue has been resolved.
• When the…