I've been having an issue with infuse on my iPad 4th gen and iPhone 5 streaming from a windows PC to an Apple TV. All of them are running the latest iOS.
The issue is subtitles are always ~0,7 seconds late which is not a big deal because the app can resend them.
the bigger issue is sometimes the subtitles freezes in a frame, and comes back at about 5 or 10 seconds.
I experienced this situation with both predownloaded subtitles and ones downloaded through infuse itself.