Thank you reyalp. Very sorry if I somehow got the builds mixed up. I will check build and splash screen before I try again next week. Another possibly useful data point would be how many images are on the card after the crash.
I made a simple test script to reboot repeatedly with autostart (attached) to see if I can reproduce this on my d10. No crashes yet.
I ran this for ~400 reboots with varying numbers of images on the card and didn't see any crashes.
Reyalp thank you for your test script, which I ran 100s of times and like you, I did not get a crash. (Splash screen on).
However, I've had further intermittent crashes at the reboot point within ultimate intervalometer script. (That is the only crash point I've ever encountered).
Is the way reboot happens within ult int somehow different?
Romlog looks the same for each crash and assert time always just after ult int reboot begins.
I rechecked that I had indeed used CHDK files from your build last time, when you found my romlog was not from build 3338.
Then I re-extracted the zip archive from your post and tried again (delete CHDK on my card, copy zip contents to the card). But the CHDK that runs is not build 3338. Splash screen after last attempt said build 3276. Not sure about previous attempts, hard to read splash screen quick enough. Is there a file in CHDK folder where I can read build number? Anything else I can check to find out why I am not getting the right build running?
Later I found my newbie mistake - duhhh! I'd been placing new build files all in the FAT32 partition. Now realise I should put only CHDK folder there, and should put DISKBOOT etc in the other partition. After doing the latter I have build 3338 running... yaaay! Boot problem remains unresolved but at least I can continue testing with the right build...