Maybe my understanding is wrong, but I think 'Ide(imageDir)' should not be in the config-file. It should be renamed to an internal variable, because the images are binded into the wrapped EXE. So changing the path by the user would violate the search for the button-images. So there is nothing to configure.
Example:
set InternalImageDir "/freewrap/images"
On Linux and other Unix platforms newlisp-tk.tcl is run unwrapped and 'Ide(imageDir)' points to an user configurable directory on that platform.
Lutz