I got the latest juce code from GitHub yesterday, and the audio handling (on iOS) seems to have been broken.
In my prepareToPlay function, samplesPerBlockExpected is 128,
but the callback from juce_AudioDeviceManager (audioDeviceIOCallback) has numSamples set to 512.
This used to work with Juce 4.0 (haven't checked 4.1 yet)
Is this a work in progress?