As "a1ex" already pointed out, there is a reason why ISO-3200 is
gone (if we can say that something that never existed is gone), and it is explained in the user guide; moreover, intermediate ISOs have now their own button (see
http://code.google.com/p/400plus/wiki/UserGuide#In_the_creative_zone), and thus there is no need to disable the shortcuts menu.
The issue you comment about the displayed value at the picture info is also commented in the user guide (
http://code.google.com/p/400plus/wiki/UserGuide#Extended_ISOs); it is a known limitation in the original firmware, and I would like to solve it, but it won't be easy.
Current intermediate ISO values are not "random" at all: there is a 1/8EV separation between them (unless I made a mistake with the math, that is). And there is a good reason to use that value: it is what the camera uses internally (and not only for ISO values, by the way, but also for shutter speeds and aperture). So basically what you have now is direct control over what the camera really does.
I would like to know why light should be measured in 1/3EV increments, in your opinion; because the only reason I could find is that someone decided, fifty years ago, to add two intermediate stops in the aperture ring of a lens. Think about that: a
mechanical limitation, from half a century ago, that is still with us. There is, on the other hand, a technical reason why 1/8 (or 1/4, or 1/2) EV values make much more sense; and I guess the people at Canon decided to use that value and round 1/3EV values to those (internally, 1/3EV is in fact 3/8EV, and 2/3EV is 5/8EV).
Anyway, if all this still does not convince you, there is no reason why you cannot continue using the old version. As far as I know, it is still available for download, at the same place where you downloaded it last time. Just go to the downloads page (
http://code.google.com/p/400plus/downloads/list), select "All downloads" in the drop-down selection, and press the "Search" button.