Outlook 2010 (32 bit) closes without warning when the user closes an email. Other emails can be open in the background and these are lost if they are new, or replies to emails. The user doesn't get any warning like "Do you want to save changes", etc
Outlook 2010 has all the updates and has service pack 2 installed. The OS is Windows 7 64 bit.
This is random, but can happen at least twice in one day. but only effects one user.