Just so Simon knows it's not a unique quirk, that happened to me also
when I imported my RTF novel document into yWriter. I got the one
chapter with nothing in it but the "C" and it was titled Prologue in
the details panel at the left. That worked out okay for me actually,
as my first chapter really *was* a prologue, and I had just renamed it
"Chapter 1" to fit with the program's requirements for importing
stuff. I simply copied and pasted that text from the next chapter
(which was correctly named Chapter 1) and pasted into the Prologue
chapter.
P