XnView Software

For example, I want to autorotate by exif tag jpg images from my camera. I select all the files in the folder and - oops! - the corresponding jpg-operations are disabled.
The reason is one or more non jpg files are in the selection (often raw or avi) which should be then manually deselected (searching for this files in the selection is annoying).

So it may be reasonable not to disable jpg operations in such example, meaning that only jpgs in the selection would be processed.

hum, or perhaps a dialog that tell you "a non jpeg file is in selection and can't processed! Continue or cancel"?

As for me, it is obvious without any conformations that choosing operations with jpegs mean that only jpegs would be processed (I can imagine only few cases when conformation may be useful rather then annoying).
But I admit that most of users may think otherwise.