I am running MATLAB R2012a on Windows 7. It recently has developed a problem where it can't save new files, or perform a "save as" on existing files. Every time I try, MATLAB freezes and I have to kill it using the task manager. I can edit and save files that already exist without a problem, and I can also create a file in the directory using fopen without a problem, so I know it isn't a permission issue. What can I do about this?