One of the sweeping cameras seems to have developed a fault in it's "home" position - the image flashes/goes black occasionally when it's pointing directly at the feeders.
I'll have a go at cleaning it out (it may just have dust in it), and wiggle some contacts, but if it doesn't help then hopefully it's still under warranty and it's a trip back to the store (don't know how I'll explain the various layers of chicken crap, dirt, dust and feathers that's probably in and all over it!)
Wish me luck!
For the meantime, there's no moving cameras :-(