The .fonts.cache-1 file is part of the Freetype font system, do a google search for "fonts.cache-1". You create it by running the fc-cache(and/or fontconfig) command. I don't have to deal with it much, so thats about all I know. You can get it at Freetype

Why it is causing problems for you I don't know, it usually runs transparently in the background. Maybe your Tk version was compiled with Freetype support, but the machine you are on dosn't have Freetype installed?