Encoding problem: PDVariableText.setValue

When assigning a value to PDField "AI_PLZ_ORT"
containing a german "Umlaut" (e.g. a/o/u-dieresis ->
äöü) acrobat reader is displaying a cedilla instead of
a udieresis. But if you select the Field (click into)
the the value is show in the right encoding.
A \374 in PDFDocEncoding (udieresis) is inserted and a
\374 in MacRomanEncoding (cedilla) is shown.
The PDF (orig.pdf) has been created on a Mac and the
Java application to modify the PDF runs under Windows
XP (PDFUtil.java, PDFUtil.class)

--
javac -cp lib/PDFBox-0.7.2.jar -source 1.3 -target 1.3
PDFUtil.java
java -cp lib/PDFBox-0.7.2.jar;. PDFUtil