Here's a puzzler for you-a team member who does not have Microsoft Office Project 2007 installed on her machine has managed to check out a project. Any guesses as to how she pulled this off?
Assuming the team member never had access to the Project 2007 client and never had permission to save a project, she may have been able to check out a project through Project Web Access. If the team member had permission and chose to edit project properties in Project Web Access, but did not check the project in upon exiting the Edit Project Properties page, it would appear to still be checked out to the team member.
So what should you do in this situation? You could ask the team member to return to Project Web Access and properly exit the Edit Project Properties page. Or, if that isn't an option, you can force a check-in on the project in question. For more information on forcing a check-in, see the following help topic: Manually check in projects and resources that are checked out by another user.