T4i won't read memory cards

[WileE39]

So this may not be ML related. I finally set up ML for my 650D. I shot about 3 days with it. My camera is now acting very strange. It will only read ONE of my several cards..Its an Eyefi card. It does not have the ML firmware on it. The cards that it will not read are acting strange in my computer as well. I attempted to reinstall ML firmware on them from my mac, and I now only have read permission on these cards. I did find a VERY old 32 MB card in my bag that the camera recognized...but when I removed it to put in my mac...same thing...read only. Any suggestions? (the card slot does NOT appear to have anything abnormal inside.)

[Walter Schulz]

Try using external cardreader. There are some reports about malfunctioning card slots in some Macs.

[dmilligan]

It's easy to accidentally flip the readonly switch on the side of the card. Please ensure this is not the problem.

[LU72]

You didn't say if you waited a few seconds or not before removing the card from the camera, but that is crucial. Removing the card from the camera before it's done doing whatever it is ML does when you open the door can lead to corrupt files/cards.