Nikon D3000 File Number Error?

My D3000 got to File Number DSC_1095, (Picture 999 in folder 100D3000) but then instead of going to DSC_1096 it reset to DSC_0001 in the new folder 101D3000.It should take up to 9999 in one folder so why has it reset now!
Any advice?

There can be many reasons for this, but why worry? As long as your images are being saved, that is the main issue.

In your cameras menu, you can choose the number of your file folder up to 999D3000. I change folder numbers when I'm shooting two different events on the same day, just to keep the photos separate.

On page 133, you will see if you press the "reset" button, it creates a new file folder and starts the next image at 0001

Also look on page 119, 125 and 179 for other reset options.

Page 138 describes how to rename your file folders