On my computers, all files of the type *.tex are associated with Scientific Workplace. But I have noticed that, occasionally, when I look at a folder that contains a bunch of these *.tex files, a couple of them fail to show Scientific Workplace as the program to which they are associated. They still work; in other words, if I double click on any of these, they open correctly in Scientific Workplace.
If I change attributes, such as making the files read only, all the correct logos appear.
Also, if I open a new lister in Opus, all the correct logos appear>
What I have described here is fairly new. I see it only in the latest versions of Opus.
Jonathan