Looks like simple case of screwed file name. Try changig it to something.pdf or something.chm and see what happens. Unless it is zip or rar archive, in which case try with something.zip or something.rar. Of course, if you use Windows, you shoud have option "Hide file extension for known file types" unchecked. BTW, that is one of most stupid Windows default settings I ewer saw. Right after some idiotic defaults in IE5 and above.