*dang*
I thought I'd just worked something out that might help. But I'd missed london.roadhog's latest posts.
So instead I'm confirming london.roadhog's results.
half-shutter -> settle -> full shutter = camera can keep shooting
full press ever and camera crashes
I used P mode and I think raw was turned off.
---
Note that the screen goes black for about 5 seconds after taking a shot.
I haven't tested burst, yet, but night scene was working in earlier tests too.
---
Note:
I suspect some of the Canon menu settings are not saved immediately (possibly not till the camera is shut down).
I had Canon image review set to hold.
I set review to off. Used CHDK and crashed the camera by doing a full shutter press (unintended)
When I switched the camera back on, review was again set to hold.
I then set it to off and turned the camera off and on.
Now review was set to off.
---
Note:
If review, in the Canon menus, is set to "hold", it will override the intervalometer script.
The script gets to take 1 photo and then, with review set to hold, it takes no more photos.
I turned review to off and now my camera is happily working with the intervalometer script.
Also zooming is ignored/overridden once the Alt button has been pressed. (This means you just need to set up the zoom for the time lapse before you switch to CHDK mode)