I have a feeling I've seen this asked before but can't find an answer...
In DO9 I have a file selected. As soon as I save this file in a different program it becomes unselected. Is there a way to keep selected files selected even if they're modified?
I don't see that here. What program(s) are you using to save the files?
Ok you're right. It only seems to happen with Visual Studio.
It will happen with any program that performs "safe saves" - that is, saving to a new file, deleting the old file, and then renaming the new file back to the original file name. To Opus it looks like the original file has been deleted (which it has), and a new one created (which it has), and it doesn't link the two together to maintain file selection.