bug in cat 5.3.0 (cygwin) on XP SP2

when 'cat' is passed several text files as parameters, it will add the 
invisible control character '^M' at the end of each lines of each file 
except the first file.

e.g.:

$ cat file1.txt file2.txt file3.txt > fileout.txt

in fileout.txt, all the lines from file2.txt and file3.txt now have a 
spurious invisible '^M' control character right before the \n.  this 
character was not present in the original files.  it can be seen by editing 
the text files with emacs.

this invisible  '^M' control character causes problems, e.g. if you pipe 
this into 'sort -u', identical lines that should be discarded are not 
discarded because they are in fact now different because of the spurious 
invisible '^M' control character added by 'cat'.

the spurious invisible '^M' control character is NOT added to the lines of 
the first file in the parameter list.

-t