Do you want to get rid of it ?

Then the "Cool Unmount Volume" extension is the solution!

Most of the time, this message appears just because an application like SimpleText has been launched from the disk you want to eject.

What the "Cool Unmount Volume" extension does, is to send a "quit" message to any application launched from the volume (like a zip volume, a cd-rom, a diskette, etc.) you want to eject, so that you don't get annoyed by this message any more. What happens with launched applications on that volume is merely the same as what happens when you shut down you Macintosh.

Try this extension: you will soon forget it! Till you register or delete it...