there's a problem if two users open a project file and both make changes and save the project.
When both users save their changes the change of the first user will be overwritten by the second user --> data loss.
Possible workarounds or fixes:
1. if the file on the disk has changed, the user should be prompted whether to overwrite the file or save the project at a different location.
used OS: WindowsXP
Let me know if you need more informations.