The only way I was able to get around the problem was to turn off the automatic backup file feature in Word 2010 while working in that document.

1. Click the File tab of the ribbon and then click Options.
2. Click Advanced at the left side of the dialog box.
3. Scroll down to the Save section and make sure the Always Create Backup Copy check box is NOT selected.
4. Optionally, also NOT select the Allow Background Saves check box.
5. Click on OK.

In addition, sometimes when you open a word file, a temporary copy is created.

Closing the document should also close the temp file.