unfortunately we won't be there on the 4th, came back home last night.
All photos downloaded fine, I have to figure out what's going on. It's a very intermittent thing, once I got an error (couple months ago) that was either error 7 or just error and I had 7 images left on my card (it went away so fast I can't be sure), this time I once saw just error and the blinking started up again but camera worked fine, at other times I didn't notice an error message but also didn't look for one. Since the camera works just fine for the next photo I can't be sure if it showed an error or not.
I'm going to take the eyefi card out first and see if that's maybe it, for the second I saw the error messages I saw no indication which card was giving the camera a pickup. I'll reformat them all in camera and will only use one card for a while, see if I can at least narrow it down to which card slot is having issues.
Also sometimes no preview image appeared after taking a photo, I had to press the play button to see what I just took. An error might have shown or not, not sure, as the message goes away so quickly. If I can't narrow things down I'll send it in for a checkup. Can't do that until end of July though, as I have an other trip coming up and am not sure Canon would be able to get this done in time. But this is a car trip with no weight limits, so I can bring my backup body and other cameras. And it's more a family trip than a photo trip, so it's not as important as a rare trip to Yellowstone and Tetons. We had a fantastic time there, such beauty! Incredible wildflowers everywhere, saw tons of bears and all the other wildlife, only wolves and moose were elusive.
2nd week was at a dude ranch, Moosehead Ranch in Jackson Hole, an incredible place, great people, fantastic place, outstanding food, beyond all expectations. Highly recommended! Not cheap, but fully worth every penny.
Thanks for all the ideas and help! If I find out what's going on I'll update this thread of course.