Yes. It happens to me all the time, but I'm not exactly sure how to reproduce/articulate the steps required to make it happen.
For me, it's something on the order of:
1) Drag an image file from a open folder to an alias of Photoshop contained a tabbed folder at the bottom of the screen
2) Close the document window in Photoshop with command-w (may have to be the only open document).
3) With Photoshop is still in the foreground, and without manually switching back to the Finder first, click on the open window of the Folder window that contains the image.
4) Click on the filename to rename it and try to enter text. The text will become editable, but the keystrokes don't have any effect. It seems that the mouse knows that the current application is the Finder, but the keboard doesn't. I can't even close the open folder window with Command-W. Then, clicking on the desktop itself (rather than the open folder windows) makes everything go back to normal.
I can't guarantee this is exactly how to reproduce this -- just how I remember it happening. This has happened at least since Mac OS 8.6, an possibly as early on as 8.1.
[This message has been edited by scott (edited 12-04-1999).]