Well dear Reader I’m really up the creek this time. Using the (so far) quite reliable Unison file synch program it’s all gone base over apex. A bunch of files which I’d done approx six to eight hours work on have all be reduced to zero bytes size in all three of my replicas (home computer, work computer, usb drive). I’m really not sure how this happened there is a Debian Bug on something that looks familiar I’m using 2.13.15 where the release notes claim that is fixed however! The problem is that the data has propagated through with zero bytes over a couple of synchronisations so all of my files are corrupted…. all I’m left with is a half completed bibtex file.