Compressor 4.1.1 mangling audio on compression to .m4a
I have been using Compressor 4.1.1 and earlier to batch compress a large number of mono 44.1 kHz 16-bit .aiff voiceover files. I am using AAC compression to create .m4a files. I have done hundreds, perhaps thousands, of these files successfully using a droplet created on my desktop with Compressor 4.1.1.
On two different computers (a brand new Macbook Pro and a 2010 Mac Pro) after the 10.9.2 update, every single one of the .m4a files I produce with Compressor 4.1.1. has a "pop" at the beginning of the resulting file on playback. There is also a small, but audible section of audio has gone missing (usually a syllable or less, depending on how closely trimmed the initial silence was).
I will report this to Apple as a bug. Does anyone else see this misbehavior?
Compressor, OS X Mavericks (10.9.2), Macbook Pro and Mac Pro