Well, the flippant answer is to "ask Microsoft", but I don't think that would be very helpful!

First, some basic questions.
- Is it only one workstation that is not closing the files properly on the Server?
- Is it only one specific application where the files are not being properly closed?
- Is the workstation stable and reliable otherwise, or is the user having to end any tasks using Task Manager?
- Is this a frequent occurance or repeatable?
...and finally...
- What versions and modules of Adagio are we talking about?