crash-message and failure after enabling blocklist plugin

[anonymous]

I am using version 5.8.9 on Ubuntu Hardy and after trying to enable the blocklist plugin, I get a crash message with following on the console.
This happenes after showing the pop-up window for downloading/updating blocklists and deluge does not actually crash,
the plugin is not enabled and the crash message keeps showing, till I shut down normally:

...
Found NetworkHealth plugin...
Found TorrentNotification plugin...
Gtk-Message: (for origin information, set GTK_DEBUG): failed to retrieve property `GtkTreeView::odd-row-color' of type `GdkColor' from rc file value "((GString*) 0x88da950)" of type `GString'
Found blocklist plugin ...
Traceback (most recent call last):
  File "/var/lib/python-support/python2.5/deluge/dialogs.py", line 310, in plugin_toggled
    self.plugins.enable_plugin(plugin_name)
  File "/var/lib/python-support/python2.5/deluge/plugins.py", line 80, in enable_plugin
    self.enabled_plugins[name] = plugin.enable(self.core, self.interface)
  File "/usr/share/deluge/plugins/BlocklistImport/__init__.py", line 29, in enable
    return BlocklistImport(path, core, interface)
  File "/usr/share/deluge/plugins/BlocklistImport/__init__.py", line 72, in __init__
    self.loadlist(fetch=self.config.get('load_after_days'))
  File "/usr/share/deluge/plugins/BlocklistImport/__init__.py", line 99, in loadlist
    if now_timestamp >= (list_timestamp + (86400 * days_update)):
TypeError: unsupported operand type(s) for *: 'int' and 'NoneType'
Cancelling
Traceback (most recent call last):
  File "/var/lib/python-support/python2.5/deluge/dialogs.py", line 317, in plugin_toggled
    self.plugins.disable_plugin(plugin_name)
  File "/var/lib/python-support/python2.5/deluge/plugins.py", line 89, in disable_plugin
    plugin = self.enabled_plugins[name]
KeyError: 'Blocklist Importer'
Applying preferences
save uploaded memory
Pickling state...
Stopping DHT...
Saving fastresume data...
Quitting the core...
core: removing torrents...
core: removing settings...
core: shutting down session...
core shut down.

[anonymous]

screenshot

[cov]

Quick fix that works for me

[mvoncken]

fix commited. Thanks cov.