I haven't had a chance to do any more video tests with fresh batteries yet - I'm actually on vacation right now so I haven't had time to do much experimentation. Will be back home on Sunday and should be doing more investigating after that.
I'll bet a small sum that this is just a depleted battery issue. Did some reading on the"bugsplatter" pdfs from box.net/chdk and the current drain during recording can easily be high enough to drag down a partially depleted set of AA cells. And the "recovery" when the load goes away is normal for batteries.
I'd offer to look at the code but I suspect by the time I got my head around it someone more experienced will have some better answers...and I don't do much C anymore and haven't touched assembly in years. But I do plan on at least setting up enough of a dev environment to be able to build from source so when/if I get some time I can browse through the code and try to get a feel for how this all works.
That's when the fun starts. For now, assume there is someone else who will look at the code.
I do seem to be able to load grids from playback mode as long as I load the smallest rulers grid first. For some reason loading that grid first always seems to work and I can then load other grids. But if I try to load any other grid first then the camera crashes. There may be something else going on that I'm missing though as to why that seems to work.
I'll try that too. The fact that it loads in shooting mode and not in playback mode should be a big enough clue once I get home to my dev machine.
Did try the HDR script today while I was out and about and it seemed to work quite well...if not a little slower than I would have hoped. But I haven't even looked at the script source yet to see if there are built in pauses or something. Really hope I can find time to look at the motion sensing script soon and figure out if this camera can do faster motion sensing, right now it's too slow to be a useful feature for me just using the default sample scripts. (by even someone slowly walking past is out of frame by the time it triggers - absolutely no chance of catching lightening.) Hopefully it's just the default settings in the sample script that cause it to be so slow right now <fingers crossed>
The guy that wrote those scripts did them at the time when there were no real "photography" scripts included in the default installation - just a lot of test scripts that ran test code. So those were added as the absolute simplest example of the four things they did - with a Lua and uBASIC version for reference. There are hundreds of better scripts on the wiki and forum if you do some searching.
The timing on the HDR script is a function of how fast you can cycle shots with a script - there are tricks to speed it up but its still going to take you several seconds to take three shots.
The Motion Detection script is totally untuned for any particular camera - you need to study the parameters and play with them to get your A1200 to work well. FWIW they seem to be dependent on ambient light level a bit too. There was an auto-tuning script for motion detection posted some time ago - I went looking for it a few weeks ago but could not find it - I need to look again. Might have been on the German forum?
If you get a good set of values that work for you, please post them here in the forum ?