Change editor button images

[tommythejoat]

We want to change the image for our image upload button in the editor from the "tree" to a camera. I thought I could do this most simply by just changing the contents of the file named insertimage.png in the images/editor folder.

However, doing that does nothing on my system. I have not yet tried disabling all the add ons, etc. but have been flushing all the cache elements I can find. Can anyone point me to where these images are protected? Are they automatically stored in a sprite cache?

I thought I could just let it age and it would eventually come in, but it has been about a week now and still no change.