Do you see the message "This post has NOT been accepted by the mailing list yet."
This means that your message hasn't reached anyone. Nabble is not affiliated in any way with iText Group. Nabble is not an official channel to post questions about iText. You should go to http://itextpdf.com/support if you want to know how to get support.
As for your question: you are using iText 2.1.7. This is a version that dates from 2009. It is more than 7 years old. It is no longer supported. Many technical problems have been fixed in the last 7 years, so you should upgrade and see if the problem persists.