Kirk - I'm using 4.6.1 on a XP Pro sp3. (Though this also happens on my 64 bit Vista unit). I've had this issue for as long as I can remember but it's not a real problem and I could never figure out WHEN/WHY it happens. As I'm editing/color coding at some point when I hit a number I start getting a sound for every image I number then at some point it stops. It's the same tone I get when ingests finish. (I have PM set to go to next image when coded). Today I noticed it stopped when I applied a crop and started again when I removed the crop - on & off like a switch over and over. But that's after it started - I did not notice when it started. Also as I was playing with this back and forth, crop, remove crop, code remove code, suddenly when I hit the number 4 I got 4 stars on the image for a couple of times then it went back to applying color - I've never seen that before.