Two issues: Runtime error when trying to Reduce Size or Optimize File. And navigation in some files is VERY SLOW.

Question

I haven't figured out if there is a pattern here, as of yet.
This happens with larger files (1500 pages and so forth) and not all the time. 
- Bookmarks may take up to 4-5 seconds to go to its page.  Scrolling up and down pages is just as painfully slow.
Even when I break the big file into smaller sections, the navigation remains slower than molasses.  
- When I try to Optimize certain files, or Reduce their size, I get a Runtime Error. I have disable the Updater (I read this could be an issue) but that made no difference.  I have also broken the larger files into 2 or 3 pieces.  One of the pieces may work out well (I can optimize and so forth) but the other(s) may not.
Thank you.
PS: I use Windows XP Pro, Service Pack 3.  I have requested an upgrade (several times) but my wishes are not their command, I am afraid.

Answer 1

HI ,Thanks for your response. That was an error in the code I posted, but wasn't the error I was trying to solve. Once correcting that error you pointed out I am getting the problems not when I send a plain text email like:
          if(!sendmultipart)
             // send a plain text message
             msg.setContent(msgText, "text/plain");
          }but when I try and send multipart messages doing this:
          else
             // send a multipart message// create and fill the first message part
                   MimeBodyPart mbp1 = new MimeBodyPart();
     mbp1.setText(msgText);
      // create and fill the second message part
     MimeBodyPart mbp3 = new MimeBodyPart();
     // attach the file to the message
     FileDataSource fds = new FileDataSource(soundfile);
     mbp3.setDataHandler(new DataHandler(fds));
     mbp3.setFileName(fds.getName());
                   Multipart mp = new MimeMultipart();
     //adds the text to the message
      mp.addBodyPart(mbp1);
      //adds the attachment to the message
      mp.addBodyPart(mbp3);
       // adds the content to the message
      msg.setContent(mp);
     }So i get the error when executing the else branch.
Can you spot any errors here? I get the same error as mentioned earlier.
Thanks a lot,
Jess