The EditCSVAction.handle fails to convert rows value into io_.StringIO because io.StringIO require 
a unicode instead of a str.
Here is the traceback:
 
TypeError: initial_value must be unicode or None, not str	Python 2.7.1
/usr/bin/python2.7
A problem occurred while running a Python script. Here is the sequence of function calls leading 
up to the error, with the most recent (innermost) call first. The exception attributes are:

/usr/lib/python2.7/site-packages/roundup/cgi/actions.py in handle(self=
<roundup.cgi.actions.EditCSVAction instance>)
  298 
  299         # do the edit
  300         rows = io_.StringIO(self.form['rows'].value)
      rows = undefined, global io_ = <module 'roundup.anypy.io_' from '/usr/lib/python2.7/site-
packages/roundup/anypy/io_.pyc'>, global StringIO = undefined, self = 
<roundup.cgi.actions.EditCSVAction instance>, global form = undefined, value = undefined
  301         reader = csv.reader(rows)
  302         found = {}

/usr/lib/python2.7/site-packages/roundup/cgi/actions.py in execute(self=
<roundup.cgi.actions.EditCSVAction instance>)
   37         """Execute the action specified by this object."""
   38         self.permission()
   39         return self.handle()
      self = <roundup.cgi.actions.EditCSVAction instance>, global handle = undefined
   40 
   41     name = ''

/usr/lib/python2.7/site-packages/roundup/cgi/client.py in handle_action(self=
<roundup.cgi.client.Client instance>)
 1140                 return getattr(self, action_klass)()
 1141             else:
 1142                 return action_klass(self).execute()
      action_klass = <class roundup.cgi.actions.EditCSVAction>, self = <roundup.cgi.client.Client 
instance>, global execute = undefined
 1143 
 1144         except (ValueError, Reject), err:

/usr/lib/python2.7/site-packages/roundup/cgi/client.py in inner_main(self=
<roundup.cgi.client.Client instance>)
  450                 # possibly handle a form submit action (may change self.classname
  451                 # and self.template, and may also append error/ok_messages)
  452                 html = self.handle_action()
      html = undefined, self = <roundup.cgi.client.Client instance>, global handle_action = 
undefined
  453 
  454                 if html: