Tools → Message Filters generates XML parsing error

[Hugh Hyatt]

Binary package hint: thunderbird

Selecting <Tools> → <Message Filters> generates a dialog box with the following message:

 XML Parsing Error: syntax error
 Location: chrome://messenger/content/FilterListDialog.xul
 Line Number 1, Column 1:

 ull);
 ^

Ubuntu 8.04 Hardy Heron
Thunderbird 2.0.0.18 (though selecting <Help> → <About> generates its own similar error:

 XML Parsing Error: undefined entity
 Location: chrome://messenger/content/aboutDialog.xul
 Line Number 1, Column 10:
          <button id="subscribe" label="&subscribeButton.label;" accesskey="&subscribeButton.accesskey;"
 ---------^
)