Jboleto - Exception

Programação Java
#1 
        java.lang.NullPointerException
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:989)
        at java.lang.Double.valueOf(Double.java:475)
        at java.lang.Double.<init>(Double.java:567)
        at org.jboleto.control.PDFGenerator.addBoleto(PDFGenerator.java:249)
        at org.jboleto.JBoleto.addBoleto(JBoleto.java:119)


com.lowagie.text.exceptions.IllegalPdfSyntaxException: Unbalanced begin/end text operators.
        at com.lowagie.text.pdf.PdfContentByte.sanityCheck(Unknown Source)
        at com.lowagie.text.pdf.PdfContentByte.reset(Unknown Source)
        at com.lowagie.text.pdf.PdfContentByte.reset(Unknown Source)
        at com.lowagie.text.pdf.PdfWriter.resetContent(Unknown Source)
        at com.lowagie.text.pdf.PdfDocument.initPage(Unknown Source)
        at com.lowagie.text.pdf.PdfDocument.newPage(Unknown Source)
        at com.lowagie.text.pdf.PdfDocument.close(Unknown Source)
        at com.lowagie.text.Document.close(Unknown Source)
        at org.jboleto.control.PDFGenerator.getBaos(PDFGenerator.java:306)
        at org.jboleto.JBoleto.writeToByteArray(JBoleto.java:147)

Alguêm ja viu esses erros? oque pode ser?

Fico no aguardo obrigado

#2