convert-ly error converting files older than 2.5

[Thomas Scharkowski]

I tried to convert some Lily 2.4 files with convert-ly version 2.7.34 
(Windows XP) and get an error. Files from version 2.5 and higher are 
processed normally.

Thomas

Message:
--
Applying conversion: 2.5.0, 2.5.1, 2.5.2, 2.5.3, 2.5.12, 2.5.13, 
Traceback (most recent call last):
  File "C:\Programme\LilyPond\usr\bin\convert-ly.py", line 276, in ?
    main ()
  File "C:\Programme\LilyPond\usr\bin\convert-ly.py", line 270, in 
main
    do_one_file (f)
  File "C:\Programme\LilyPond\usr\bin\convert-ly.py", line 173, in 
do_one_file
    (last, result) = do_conversion (infile.read (), from_version, 
to_version)
  File "C:\Programme\LilyPond\usr\bin\convert-ly.py", line 115, in 
do_conversion
    str = x[1] (str)
  File "C:\Programme\LilyPond\usr\bin\convertrules.py", line 2413, in 
conv
    de_ascii = codecs.getdecoder ('ascii')
  File "/usr/lib/python2.4/codecs.py", line 729, in getdecoder
--