We ended up getting a core due to the same error today. 1XHEXCPMODULE Compiling method: com/lowagie/text/pdf/PdfDocument.writeLineToContent.(Lcom/lowagie/text/pdf/PdfLine;Lcom/lowagie/text/pdf/PdfContentByte;Lcom/lowagie/text/pdf/PdfContentByte;[Ljava/lang/Object;F)VWe are on Jasperserver 3.7.0 on IBM JDK 1.6 64 bit running on AIX 5.3. We run Jasper under Tomcat 6.0.20. Opened a support case with jasper.