<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Thank you for reporting this problem to us. I managed to reproduce the problem on my side. Your request has been linked to the appropriate issue. You will be notified as soon as it is resolved. As a workaround of this problem you can try removing brackets around numbers, after removing and setting culture all works fine:
// Set culture
CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
// Open document.
Document doc = new Document("yourDoc.docx");
Thread.CurrentThread.CurrentCulture = currentCulture;