UnicodeDecodeError problem when run BitTorrent module

hello guys, i have a problem that when i compile one of bittornado source file named:btdownloadgui.py and i get such a error message:

BitTorrent T-0.3.15 (BitTornado)
OS: win32
Python version: 2.4.3 (#69, Mar 29 2006, 17:35:34) [MSC v.1310 32 bit (Intel)]
wxWindows version: 2.6.3.3

Traceback (most recent call last):
  File "C:\BitTornado-0.3.15\BitTornado-CVS\btdownloadgui.py", line 2334, in _next
    savedas = dow.saveAs(choosefile, d.newpath)
  File "C:\BitTornado-0.3.15\BitTornado-CVS\BitTornado\download_bt1.py", line 409, in saveAs
    if path.exists(path.join(file, x['path'][0])):
  File "C:\Python24\lib\ntpath.py", line 102, in join
    path += "\\" + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xb9 in position 1: ordinal not in range(128)

of those errors: one is from bittornado source file btdownloadgui.py itself,and one is from the the bittornado library,also one is from the python library. weird,isn't it?
later i get something more about bittorrent encodings and decodings,utf-8,utf-16,ascii,latin.etc.and i try almost all of these decodings and encodings,such as use decode('utf-8'),or encode('utf-16')etc.and those doings donot come out effectively.
later i use

try:
    from sys import getfilesystemencoding
    ENCODING = getfilesystemencoding()
except:
    from sys import getdefaultencoding
    ENCODING = getdefaultencoding()

in the btdowngui.py source file,however the bug remains.
does it means the bittornado library or the python library itself is misleading?
so help.
thanks if anyone can be useful.
regards,
jolley