I am successfully using my Eye-Fi 8GB Pro X2 with my Canon 1D Mark IV, sending images to my iPad through WiFi and awaiting Direct Connect later this year. In this regard, I am very happy I have achieved success.
However, the Eye-Fi website camera compatibility page says this about the Canon 1D Mark IV:
"When used with an Eye-Fi card, the Canon EOS-1D Mark IV stays powered on until wireless media uploads are complete, has an onscreen icon, and offers the ability to enable/disable Eye-Fi Card Wi-Fi via the camera menu."
I have found that this is not the case. I powered off the Mark IV before an upload finished and it killed the upload. I see no on-screen icon. I see no way to enable/disable Eye-Fi Card Wi-Fi via any camera menu.
I am definitely running the latest firmware (1.0.
on the Mark IV and Eye-Fi card (4.2172).
Is it possible that the Pro version of the card is NOT "Eye-Fi" connected to the Canon 1D Mark IV? (in other words, maybe the non-pro card is connected but the Pro is not)?
OR - Am I doing something wrong here to enable this feature set on the Mark IV?