1ds MK2 & 8gb cf card problem

I just picked up a mint (8 actuation backup camera for a hobbyist) 1ds mk2 a couple of weeks ago. I also just bought an 8gb cf card (silicon power, a brand I've always used with no issues). However yesterday when I combined the two (I hadn't had the new firmware installed so I installed the newest firmware is installed and issue still happens) I could shoot fine but if I changed lenses, all my shots were lost off the card (I had to use a photo recovery program to get them back). It wasn't switching to the sd card because I wasn't using the sd card.

I came home and did some tests and every time I took a shot, turned off the camera and turned it back on, the shots were still there but if I turned off the camera and removed the lens, the shots were lost.

It doesn't do it with another (different brand) 8gb card and it doesn't do it with my 4gb cards (same brand & sandisk).

With the help of the RRTP gang, we've pretty much narrowed it down to the card but I'm curious if anyone has ever experienced this before? Or heard of it? If not, then this thread can just be a document in case anyone else comes across this problem...and if so, did it turn out to be the card? Also, the 8gb card works fine on my 1DM3. I can remove the lens and the photos are still there when I turn the camera back on. (which makes me wonder why it works fine on the M3 and not on the other camera...I just want to be sure it's not a camera problem since I'm using it for paid gigs...it needs to work properly).

Very strange issue. I've never heard of a problem like that....Please fill us in on the solution once you figure it out

I'm having the same issue.
Just got a 1D MkII N and images are disappearing off the card, which coincides mostly with lens changes, not all images though. I'm in the process of figuring out whether it is camera or card.
Using a silicon power 4gig card.

I'm wondering if it's the card brand. I haven't had any trouble with my other cards on this camera (though some of them are the silicon power 4gb) including other 8gb cards.

do post your findings though, if it's not (or is) the card

Permagrin wrote in post #5991864
I'm wondering if it's the card brand. I haven't had any trouble with my other cards on this camera (though some of them are the silicon power 4gb) including other 8gb cards.

When in doubt... SanDisk

Permagrin wrote in post #5991867
do post your findings though, if it's not (or is) the card

Tried a day of multiple lens changes, with the same CF card, but added a SD card and wrote to both. All images were kept on both cards

Had that problem years ago with my 10D and a 1GB card that lost a full shoots images when I changed lenses(I was mad as I could not re-shoot). Got rid of the card(cannot remember the brand but was one of the cheaper ones) and never had a problem again. Never had the problem with my 1Ds Mk II, although I only use 2GB cards.

Well more images lost with a lens change, happened a couple more times. I was writing to both cards. All images kept on the SD card, a few lost on the CF.

Just bought a SanDisk 4G CF card, will see if that makes a difference.

I bought some sandisk extreme iii's and no issues at all with them. Hope yours works out too.

Do you turn the camera off before changing the lens?

Mark_Cohran wrote in post #6068386
Do you turn the camera off before changing the lens?

Always yes, but I did test it both ways & it didn't matter if I turned it off or left it on...it was so weird. If I just shut off the camera it was fine but if I removed the lens it lost the photos on the card. (and it only happened with that one card)

I've tried both ways as well.
Sometimes lose none, sometimes 4, sometimes 20, seems to be random but always around a lens change for some reason.

This could be one of the strangest things I have ever heard. Sounds like It must be the cards, from what both have deduced, but it makes no sense at all.

Well, my experience in electronics leads me to believe that the card is especially sensitive to power spikes. Attaching and detaching the lens would certainly change the power demand on the camera system, but what I don't understand is why it would do it if the camera is turned off when you change the lens.