I am currently using Draftsight 2013 and have been able to export my drawing 'sheets' quite successfully to pdf files, until today!

I think I have a 'blip' in my software that is only taking 'part' of my drawing sheets into pdf format. Everything I put on the 'sheet' is being exported, but the drawing/s inside the 'viewport' are not. If anyone has any suggestions as to what I might have done wrong, I would really appreciate your comments.
Cheers
Deborah