The following feature is exhibited by The GIMP 2.6.8 running on Windows 2000, Windows XP, Windows 7 and Mac OS X.

There would appear to be a problem (or at least inconsistent behaviour) when the "Save tools options on exit" option is selected.

Starting with all of the tools set to their default settings (using "Edit/Preferences/Tool Options/Reset Saved Tool Options to Default Values" and then closing and re-start The GIMP) the following example illustrates the problem:

Select the pencil tool and change its layer mode from "Normal" to "Dissolve" (in practice the bug shows with any mode other than "Normal"). Then close The GIMP whilst the pencil tool is still selected.

Start The GIMP; the layer mode of all of the tools will have changed to "Dissolve".

Reselect the pencil tool and change its layer mode back to "Normal", then, with the pencil tool still selected, close The GIMP.

Start The GIMP. The pencil tool layer mode will be "Normal" but the layer mode for all of the other tools will still be "Dissolve".

A similar problem exists for the opacity setting in that closing The GIMP with the selected tool having an opacity of less than 100% will set the opacity of all of the tools to this same value. Again this is not reversible by the selected tool having an opacity of 100% when closing The GIMP.

Given that the tool-options folder contains separate files for all of the tools
the settings should be stored on a per tool basis (failing that then at least all of the tool layer modes should be set to "Normal" and the opacities to 100% when these settings apply to the tool selected when The GIMP is closed).

Once this problem has occurred then closing The GIMP with one of the tools with the non-normal layer mode selected affects the layer mode of all tools. On some of the tools the layer mode is greyed out so that it can't be changed (I am not saying that this is a problem) - these are the ones that catch me out when I next use The GIMP and wonder why the tool that I have selected is having no effect - until I notice that the layer mode is not set to "Normal".

Interestingly, if the layer mode and/or opacity of a tool is altered from the default settings but that tool is not the one selected when The GIMP is closed then the settings for that tool are saved correctly and none of the other tools are affected (assuming that the tool that is selected when The GIMP is closed is set to "Normal" and 100%).

Changing the brush of the selected tool from the default size 11 circle does not seem to have the same affect - only the selected tool is altered.

(Apologies if this has already been reported)