1. Try to retarget an existing bug to the non-existent "launchpad-infrastructure" project.
2. On the resulting error page, observe that there is a menu of suggestions with two items: launchpad-development-infrastructure and qprocd.
3. Choose either of the items.
What was expected: The Launchpad ID of the selected item should be copied into the text field.
What happened: Nothing at all.
This is in Safari 1.3 with JavaScript turned on, but the same problem would occur in any browser with JavaScript turned off. A better solution would be to present the suggestions as text ("Did you mean: ___, ___, ___"), so that they can be copied and pasted into the field. Unobtrusive JavaScript can then turn the text into links that, when clicked, change the text in the field.
I have confirmed this on Safara 2.0.4 on OS X 10.4