AI Servo & One Stop Disappearing

I had a very strange encounter today. Last week a friend of mine picked up a 180mm f/3.5L Macro lens. He mounted it on his 1DsIII and he was doing macro shots when he noticed that his focus tracking mode had disappeared.

We figured there was some sort of contact issue. We mounted it on my 1DsII as a test, and as soon as you get into the minimum focusing area (where you still lock focus) the AI Servo or One Stop lights both disappear. [[This is on the LED on the camera]]

You have to reset the camera or refocus on something very far away manually to get either mode back.

Anyone else see this behavior?

If you by LED actually mean LCD, the status display on top of the camera, then if both One Shot and Servo AF disappears it implies that the camera is convinced that the lens is set to MF.

Yes, sorry I mean LCD. Why would both cameras think the lens is in manual mode? It's a pretty good fit on mount so I can't say it's a problem with the mount being loose and the contacts coming off.

Is it possible you were actually within the MFD? If you are too close the focus indicators won't light up -- is this what you are referring to, or are you saying the AF mode description on the top LCD goes away, or are you talking about something in Live View?

It would be at the edge of the MFD, but still outside it since we could get and keep focus manually.

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Did you flip the AF/MF switch on the lens a couple of times? I've had some lens where that contact didn't make contact reliably, but recovered after being used a couple of times.

What you show in the picture is indeed the camera's way of telling you that you are in manual focus. Cameras with live view or Quick settings will show you "Manual focus" or something similar on their rear screens, if you try to select AF method when the lens is in MF.

Yes, we tried mounting and remounting the lens, switching AF/MF switch on the lens. It still does it. On two different 1D bodies.

Yes I realize that's how the camera switch to manual mode, but since the lens isn't in manual mode ... hence the post.

Just by moving closer to the subject why would the camera lose AF yet still be able to focus -- 1:1 is the lowest the ring goes, yet about 1/4 turn away from 1:1 the body switches to this weird "manual" mode.

I don't feel so bad now that I have everyone else stumped too. This isn't some odd normal behavior. Either he has to live with it, which I don't think he does or he has to send in both the body and the lens in to see if Canon can explain it.

I'll mount it on 1DIV, since that has live view and see what it says. We haven't tried non 1Ds yet.