update-notifier doesn't handle secured .list files gracefully

Binary package hint: update-notifier

Description: Ubuntu 8.04.1
Release: 8.04
update-notifier:
  Installed: 0.70.9
  Candidate: 0.70.9
  Version table:
 *** 0.70.9 0
        500 http://us.archive.ubuntu.com hardy-updates/main Packages
        100 /var/lib/dpkg/status
     0.70.7 0
        500 http://us.archive.ubuntu.com hardy/main Packages

ubunet development has moved to a different configuration for a private PPA. As part of this, repository info is now in

/etc/apt/sources.list.d/ubunet.list

Since username and password are kept in ubunet.list, it is set to chmod 600.

Unfortunately this appears to cause problems for update-notifier, as it shows orange "updates available"

Clicking on the icon to retrieve updated results in
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Could not initialize the package information

A unresolvable problem occurred while initializing the package information.

Please report this bug against the 'update-manager' package and include the following error message:

'E:Opening /etc/apt/sources.list.d/ubunet.list - ifstream::ifstream (13 Permission denied), E:The list of sources could not be read.'
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acknowledging this dialog closes update manager.

This sequence of events is probably happening because update-notifier is trying to read the file prior to prompting for su creds. It should handle this with a credentials prompt, or some other manner that doesn't result in unceremonious exit.

sudo apt-get (etc) does get the updates, but update-notifier is still showing "updates ready" Mousing over it in this state gives a tooltip of

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An error occured, please run Package Manager from the right-click menu or apt-get in a terminal to see what is wrong. The error mesage was: ' Error: Opening the cache (E:Opening /etc/apt/sources.list.d/ubunet.list - ifstream::ifstream (13 Permission denied), E: the list of sources could not be read.)'This usually means that your installed packages have unmet dependencies
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Neither suggestion in the tooltip clears the status.