Hello!

In dired-mode file names and directory names are displayed in  
different faces, for file names:

	There are text properties here:
	  auto-composed        t
	  fontified            t
	  help-echo            "mouse-2: visit this file in other window"
	  mouse-face           highlight

for directory names:

	  auto-composed        t
	  face                 dired-directory
	  fontified            t
	  help-echo            "mouse-2: visit this file in other window"
	  mouse-face           highlight

When the cursor is on the same character, x, I get for the directory  
name's x:

	        character: x (120, #o170, #x78)
	preferred charset: ascii (ASCII (ISO646 IRV))
	       code point: 0x78
	           syntax: w 	which means: word
	         category: a:ASCII graphic characters 32-126 (ISO646 IRV:1983 
[4/0]) l:Latin
			   r:Japanese roman
	      buffer code: #x78
	        file code: not encodable by coding system utf-8-unix
	          display: by this font (glyph code)
	      
lucidatypewriter:pixelsize=10:foundry=b&h:weight=medium:slant=r:width=no 
rmal (#x59)

and for the file name's x:

	        character: x (120, #o170, #x78)
	preferred charset: ascii (ASCII (ISO646 IRV))
	       code point: 0x78
	           syntax: w 	which means: word
	         category: a:ASCII graphic characters 32-126 (ISO646 IRV:1983 
[4/0]) l:Latin
			   r:Japanese roman
	      buffer code: #x78
	        file code: not encodable by coding system utf-8-unix
	          display: by this font (glyph code)
	      
lucidatypewriter:pixelsize=10:foundry=b&h:weight=medium:slant=r:width=no 
rmal (#x59)

It looks quite equal. But when I look at both names in dired buffer I  
see differences that obviously come from different fonts used, which  
is not reported as can be seen above:



Another effect is that text file names get scrambled or partly  
extinguished thought that green background when the mouse cursor  
moves over the names:



And then the names of directories are completely wrong when the mouse  
cursor hovers above such an item. The change in name happens  
simultaneously with the appearing of the green background:



All tests done with src/emacs -Q. The different background colours  
come from default- and initial-frame-alist settings done in *scratch*  
buffer. Looking with an electronic magnifier glass I can see that the  
glyphs of the directory and sym-link names are anti-aliased (as are  
the italic names of the text properties items in *Help* buffer, or  
the incredibly RED group Write permission), while the other glyphs  
seem to come from a bitmapped font: every pixel has the same  
intensity level.


BTW, de-composed characters in Mac OS X HFS+ file names are shown as  
their basic Latin glyphs without further "decoration."

--
Greetings

   Pete

Isn't vi that text editor with two modes... one that beeps and one  
that corrupts your file?
				– Dan Jacobson, on comp.os.linux.advocacy