[Spanish] sobre TileCahe que no funciona

[PB]

Hola Colisteros,
En mi afán de hacer de mi iMac un ordenador "bonito" y funcional en
temas de FOSS4G, después de echar a andar con relativo éxito
GeoWebCache me puse con TileCache (que había abandonado hace un
tiempo)
Bueno la cosa es que al parecer ya todo debería funcionar pero...

si invoco tilecache.py de este modo
http://pb.ohc.cu/tilecache/tilecache.py/1.0.0/basic/0/0/0.png me pone:

An error occurred: HTTP Error 407: Proxy Authentication Required ( The
ISA Server requires authorization to fulfill the request. Access to
the Web Proxy filter is denied.  )
  File "Library/WebServer/tilecache/TileCache/Service.py", line 256,
in modPythonHandler
    host )
  File "Library/WebServer/tilecache/TileCache/Service.py", line 208,
in dispatchRequest
    return self.renderTile(tile, params.has_key('FORCE'))
  File "Library/WebServer/tilecache/TileCache/Service.py", line 138,
in renderTile
    data = layer.render(tile, force=force)
  File "Library/WebServer/tilecache/TileCache/Layer.py", line 443, in render
    return self.renderTile(tile)
  File "Library/WebServer/tilecache/TileCache/Layers/WMS.py", line 29,
in renderTile
    tile.data, response = wms.fetch()
  File "Library/WebServer/tilecache/TileCache/Client.py", line 58, in fetch
    response = self.client.open(urlrequest)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/urllib2.py",
line 387, in open
    response = meth(req, response)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/urllib2.py",
line 498, in http_response
    'http', request, response, code, msg, hdrs)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/urllib2.py",
line 425, in error
    return self._call_chain(*args)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/urllib2.py",
line 360, in _call_chain
    result = func(*args)
  File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/urllib2.py",
line 506, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)

En el log de errores de Apache no pone nada, no se entera. En el log
de accesos pone: "GET /tilecache/tilecache.cgi/1.0.0/basic/0/0/0.png
HTTP/1.1" 500 533

Si lo invoco del modo cgi
http://pb.ohc.cu/tilecache/tilecache.cgi/1.0.0/basic/0/0/0.png pone:

Internal Server Error
The server encountered an internal error or misconfiguration and was
unable to complete your request.
Please contact the server administrator, pb en dic.ohc.cu and inform them
of the time the error occurred, and anything you might have done that
may have caused the error.
More information about this error may be available in the server error log.

En el log de errores de Apache pone: (13)Permission denied: exec of
'/Library/WebServer/tilecache/tilecache.cgi' failed sin embargo ya
(sudo chmod 777 tilecache/*) y nada

¿Alguna idea de qué puede estar pasando?
Sospecho que los de Sistemas tienen algo que ver con esto.

ss
PB