I have been running Trackuino on my a540. The script is designed for digic III/IV. My 540 is digic II.
The script works partly for me: It will autofocus, and take successive user-defined number of photos; it will take photos and then switch to video.
However, it is intended to cycle through photos and videos, on my 540, the photos are taken; the video starts; but the video does not stop. I have to remove the batteries.
I wonder if this is a digic/II/III difference, or whether I might not be following the directions correctly.