mozilla sometimes doesnt follow the correct procedure for unknown file types (eg rars/zips) where if you click a link to them it will try and load an ascii filtered display of the file
i guess its related to that, after all it is told by the extension that its a text file not a graphic, so its ie really that is to blame (doing something it shouldnt do) rather than other browsers that are at fault
you would be best to see if your isp offers you any webspace (almost all ive seen offer some) and just put it on there