CS4 always opens a new file as another tab in the same window as my active existing file. Even if I have no files open and attempt to open more than one file at a time, PS insists on opening them all with tabs inside the same window. How can I set PS CS4 so that the default is to open each file in its own window? I cannot find any reference to it in Preferences and, if I have no file open, the command is greyed out so I cannot set it as a default that way.