Cannot get history brush to work at all

Hi,

I'm using Photoshop CS 8.0 on system 10.3.2. I've almost never had a problem in photoshop, but cannot get the history brush to work at all.

Here's what I'm doing:

1. Opening a psd file
2. making a new layer and painting on it.
3. I take a snapshot of what I've done so far
4. Then, in the history palette I click on the snapshot of the file as it was when I opened it so that the little blue slider appears on the left of the thumbnail.
5. Then I click on the left of my newer snapshot so that the history brush icon appears.

Technically I should now be able to paint from new snapshot onto my older snapshot state. But nothing happens!

I'm stumped. I've read through photoshop help and followed the instructions step by step, over and over. What am I doing wrong?

Any help appreciated.

Thanks.

Sally,

First of all, this is the Win side of the Photoshop forum.

Secondly, the fault lies when you create a new layer. When you did that, and then revert to your start image, you have no history, because there is no new layer in your original image.

Skip making a new layer.

Mathias