Sequence:
- Create a new .c file in the Atmel Studio editor;
- Save it (or edit an existing file, then 'Save As...');
- 'Add existing item' to add the new file to the Project.
Now, if I press Ctrl+F7 in the editor window with my new file, it does nothing - it does not start a compile.
If I right-click the file in the Project, I can use the 'Compile' context menu option to compile it - but it does not save the source from the editor window first!
After a while, it does all start working properly - but I haven't yet worked out what exactly is the trigger...