It would appear that Magnus Plus doesn't run on N900s that have kernel-power v50 installed. The application starts to initialize the camera (click noises) and after a bit just shuts down quietly. dmesg is full of sbl overflow and omap-iommu errors.

It worked fine when I hadn't yet updated from v49 to v50, and I can say it is a great w-i-p application. Thumbs up. And this isn't the first camera-based application not to take kindly to kp50.

[Edit] I retract... somehow, it works again. Darn! This is my first false alarm TMO message.