Strange Teledisk question

Hi folks, For the last few weeks I?ve been helping the owner of a PPG2.2 synthesizer get the ?computer? side of it, a Waveterm A, running. The Waveterm is a 6809-based single board computer running FLEX that was designed to use 8? drives, then at some point they modified it slightly to use 5.25? HD drives instead but changed very little - to connect up to the main board they made a 34-50pin adapter. The drives are YE-Data YD380 with a Shugart interface so without some sort of signal bender like a DBit FDADAP I couldn?t just plug them into a PC. However, the YE-Data YD380B has an IBM interface so we used one of those, same mechanism so we figured it should work. All the disk images for the Waveterm have been created using programs written by PPG users. For some reason any disk we wrote with them wouldn?t read correctly in the machine itself UNTIL we made a new image of that disk using Teledisk 2.15 then re-wrote it back to the same floppy. My question is why should that make so much of a difference between working and non-working disks? Trivia: for anyone aware of the 80s UK Music industry this very machine was used for the hit ?You spin me round (like a record)? by Dead Or Alive. -- adrian/witchy Owner of Binary Dinosaurs, the UK's biggest home computer collection? t: @binarydinosaurs f: facebook.com/binarydinosaurs w: www.binarydinosaurs.co.uk