I have a user who is having an issue when trying to send attachments using Outlook 2007. Here's the problem: she creates a new email message and adds the correct recipients. She then attaches 1 PDF and 1 XLS file. Upon pressing Send, the 1 PDF is removed and the XLS file is duplicated, so instead of the recipients receiving one of each, they receive 2 identical Excel files. When the user sees this issue in her sent box, it shows 2 XLS documents. She removes one and readds the PDF, resends and it goes through fine.

This issue is very difficult to replicate since it does not happen all the time, even if sending the same documents to the same people.

Does anyone have any idea where to start with this or what the problem might be? Any help would be greatly appreciated!
Thanks in advance!