I wrote an app similar to this back on the 6680 for two reasons: 1. To learn how to write an S60 app. 2. To compensate for my presbyopia.
The first thing I learned was that it is very difficult to get enough information to write an app that controls the camera. Soon after getting the info needed I discovered that my app wouldn't work on newer models. In fact, the older api was almost worthless. It is only supposition, but I'm guessing you just hit the same issue. Some 3.0 phones work but 3.1 phones (at least those I've tried) don't. What is it about us that we can't generate an API that doesn't need modification or abandonment for each new phone model? (Rhetorical question.)
Regarding the app itself, you did a much better job than I did! It does what I need and a little bit more (on the N95 only.)
The only reason you don't get 5 stars from me is that I'd prefer a background-resident mode that would allow me to hold down the camera shutter button and have this app start up and remain active until I release the button.