I experienced the same problem today.
I thought I must have done something wrong but I couldn’t figure what. This explains it.
iOS 7.4 on an ipad air with more than 25gb available.
All other apps closed and airplane mode switched on.
I was actually only dealing with three audio tracks and no effects which is a bit scary.
We need the confidence that our recordings (especially audio recordings) are accurately captured.
It doesn’t get anymore basic than this.
thanks for your attention.