Cannot access file because it is being used by another process : DFSR

Question

I’m getting an error with my single thread C# 4.0 desktop application. When I try to save a file, I’m getting the following error :

The process cannot access the file because it is being used by another process.

We have turned off DFSR in order to test, and the problem was solved.

My application is using SDL's dll (Trados Studio) and the error also occurs in Trados Studio.

So my question is: Is there something that I can do with DFSR to solve my issue or is this something related to the application itself?

EDIT

var project = new FileBasedProject(this.GetInfoForTemplateProject(projectName, projectFolder, projectDueDate), template);

/* ... */

project.GetTranslationProviderConfiguration();
project.UpdateTranslationProviderConfiguration(tmConfig);

project.Save();

My problem occurs at project.Save(). FileBasedProject is a class of the third party librairy (SDL Trados). The file that I'm accessing is a project file (.sdlproj)