Import activity using external ID as key does not work with households

Importing activity for a household using external ID as key does NOT work in civicrm 2.2.0.
It does not work on the civicrm demo site either (not sure which version that is running) - http://drupal.demo.civicrm.org

Using the Contact ID as key works just fine for Households and Individuals.
Using external ID as key works for individuals only, NOT for households.

To replicate:
Add an external ID to a household (use 1024, if using the example attached file)
Go to Import/Activity
Select the attached (downloaded) file
Select "First row contains column headers"
Select "DD/MM/YYYY" as date format (I'm a "southerner")
Continue and import - you'll get an error stating that "No matching Contact found for (1024)" in the error file that's generated.

Cheers,
Marty.