My Canon 10D suddenly changed its way of numbering the frames. One day in july 03 I took a picture with the number 128_2801.CRW. Next frame, half an hour later was CRW_2802.CRW. "128" was gone! I did not think of it then. But now I passed from CRW_9999.CRW to CRW_0001.CRW and then I understood that soon I will be at frame number 9999 again.
In Capture One LE I found in "capture info" that the frames werer numbered 5xxxxxxx2-128.2801 and 5xxxxxxx2-128.2802, where 5xxxxxxx2 is the body number. So "128" was still there!
And now I Find 5xxxxxxx2-300.99999 and 5xxxxxxx2-301.0001
so the camera still gives uniqe numbers to the frames.
But it does not show in ordinary file handling.
I did not update the firmware at that time. Later that year when I did, the numbering did not change.
JPG-pictures are numbered IMG_1234.JPG, but in the beginning 123_1223.JPG.
Can anyone explain?