Vowel with Umlaut

[GRAEME F ST CLAIR]

I'm trying to include an o-umlaut in the header, so:-

\header {
  title = "Blah Blah"
  poet = "Words: Aloysius Schlör"

but all I get is "Schlr" with some error msgs, so:-

Preprocessing graphical objects...
programming error: Glyph has no name, but font supports 
glyph naming.
Skipping glyph U+FFFFFFFF, file C:/Program Files 
(x86)/LilyPond/usr/share/lilypond/current/fonts/otf/CenturySchL-Roma.otf
continuing, cross fingers
Finding the ideal number of pages...
Fitting music on 1 page...
Drawing systems...
Layout output to `/music/scores/To_Jesus_heart.ps'...
warning: Conversion of string `Words: Aloysius Schlör' to 
UTF-16be failed: Invalid byte sequence in conversion input

I'm sure there's a perfectly simple way to fix this, but I 
haven't enough knowledge yet, tho I did google 
lilypond.org a little.

Rgds, GFStC.