Psycho,
If and when you want to test the actual rich edit content, you actually select the entire content, write it to a memory buffer THEN write it to disk. If you use the STREAMOUT based method, it changes the line terminator to a CR-LF pair.
Particularly if you are using a richedit 2 or later you need to see what is in the control to be able to select pieces of text and write it to disk. If you directly save a buffer, it DOES NOT alter the line terminator.
As I mentioned from at least Win2000 upwards, richedit 1 is emulated by the later DLL and is not entirely consistent with the earlier Win9x versions, mainly because the later versions also handle UNICODE. Unless you are writing code for Win95OEM, there is little reason to use the earlier version as the emulation is buggy. The later richedit 2/3 performs better, is faster and can do more, just for example multilevel undo/redo but also be warned that if you select this style, its internally different to other styles and makes a mess of the last line's line terminator. This in turn messes up line reporting on the last line which is where an editor is often used while composing text.
If I did not need drag and drop and multilevel undo/redo I would use a normal edit control as they are easier to use and far more consistent.