[admin (no pm's please)]

This restriction should have no really unpleasant impact, as you do have 4 template slots to edit.

The reasoning is that it should bring some clarity to supporting the system as we will be able to see whether a system template is being used or a user template.

I was tempted to change the image upload system to start allowing overwriting of images in the user template slots. But there is an argument that says the system is working, and the images people will want to use in themes for their forums and may actually be common to all the templates they want to use. e.g. a logo may be used in all template slots. So why rock the boat? Under phpbb3 it is easy enough to change what image is used for topics etc, the need to overwrite is basically not there any longer.