5DIV- Custom settings won't stick!

Anyone else experiencing this?
I've been using the C1-3 settings on my former MkII and current MkIV for years, and find them invaluable. But with the latter, some of the settings (ISO, etc) are changing even though I always make sure to register them before turning the camera off. Thought it was my imagination at first, but no. I even had the “beep” become enabled yesterday, which I haven't had turned on for my cameras since my 4D. Getting very frustrating and annoying and I anticipate sending it in to Canon once my “season” is over.
What gives??

If you are certain you are doing things correctly, then I'd flash the firmware or upgrade if you haven't. Write down anything really custom as you will likely have to reprogram the custom settings. The guts of the camera is a computer, dedicated yes but like any PC a problem can develop that a reboot or firmware reflash will fix. The firmware can be found at https://www.usa.canon.​com …subtab=download​s-firmware.

The latest version is 1.04 from April but again if you are certain you are doing things correctly do a reflash.

Firmware is current, but if you're suggesting a re-install I'll try it. Thanks.

There was a thread about two weeks back where someone with a 7D had an LCD problem (Canon 7d lcd screen will not come on; see https://photography-on-the.net …showthread.php?​p=18459387). The person got quite a bit of help, all of which was unsuccessful and was about to return the camera for service. He reflashed the firmware and the problem was eliminated. His firmware, before and after, was the same version.

Trout Bum wrote in post #18466443
Thought it was my imagination at first, but no. I even had the “beep” become enabled yesterday, which I haven't had turned on for my cameras since my 4D.

Well, maybe you are hallucinating the whole thing. There has never been any EOS 4D either...

Sorry, I just couldn't resist...

Just in case, if you can remove the clock battery in the 5DIV, I would do that as well as the main battery, re-install them and then to a firmware update (even to the same firmware).

Apart from going back to a previous firmware and then to the current, that is the most amount of 'reset' that I think you can do.

If you do end up sending it in, trying to get something repeatable could help tremendously if Canon can't immediately detect an error.

5Div has only a main battery, no "clock" battery.

apersson850 wrote in post #18466758
Well, maybe you are hallucinating the whole thing. There has never been any EOS 4D either...

Sorry, I just couldn't resist...

Good catch. Guess it was a 40D— I hope!

Can I really expect to lose all my settings? That would be a major PIA— Don't recall that happening with firmware upgrades I've done.

In most cases, when you do a firmware upgrade, the new firmware can handle the old data in the camera and continue with that.
But if you downgrade the firmware, then the older firmware doesn't always understand the newer data structure (read: if it has changed). Thus it may protect the settings data integrity by simply return to factory defaults.

apersson850 wrote in post #18467149
In most cases, when you do a firmware upgrade, the new firmware can handle the old data in the camera and continue with that.
But if you downgrade the firmware, then the older firmware doesn't always understand the newer data structure (read: if it has changed). Thus it may protect the settings data integrity by simply return to factory defaults.

Actually this is a good point. To be completely safe, you should reset to default settings before downgrading software. I believe Canon actually tests it this way so defaults are backwards comparable, even if the default does not exist in the older software (I got this from magic Lantern forums), we had to downgrade the 5DIII software at one point to use Magic Lantern.

If you send it to Canon and they do anything with it, they will reset it to defaults anyway.

Trout Bum wrote in post #18467130
Can I really expect to lose all my settings? That would be a major PIA— Don't recall that happening with firmware upgrades I've done.

Print and use the content at https://photographylif​e.com …canon-5d-mark-iv-settings as a guide and write down your settings, then write down your "Custom" stuff as well. The reflash. It probably will retain things, but you have your settings written down just in case.