Canon has posted a firmware update for the 1D Mark IV. Firmware version 1.1.0 resolves the following issues.
- Improves writing/reading speeds when using UDMA 7-compatible CF cards.
- Fixes a phenomenon where the ability to shoot movies may be stopped under the following conditions:
- When using high-capacity (32 GB or greater) CF cards with little available space remaining and the user attempts to start shooting movies; or
- When the camera’s battery is removed and reinserted into the camera and the user immediately attempts to start shooting movies.
- Corrects misspellings in the menu screens displayed in Arabic and Portuguese languages (applies to models outside of the the Japanese market only).
You can find the download info on Canon’s website.