Canon released the latest firmware patch for the 5D Mark II. Nothing changes drastically in 2.09, only a few specific errors are corrected.
1. Improves writing/reading speeds when using UDMA 7-compatible CF cards.
2. Fixes a phenomenon where the IS function will not work when custom function C.Fn III-2 is set to [5: IS start] and the lens attached does not have an AF stop button. This is because custom function C.Fn III-2 allows users to assign IS start to the AF stop button on the lens
3. Corrects misspellings in the menu screens displayed in Arabic, Portuguese, Spanish, and Thai languages.
Download the latest firmware here.