CMS7 logs many warnings "Tried to retrieve a localized string for a component that has not yet been added to the page"

The CMS logs many of the same warnings during rendering:

19.05.2011 09:57:13 WARN [org.apache.wicket.Localizer.getStringIgnoreSettings():198] Tried to retrieve a localized string for a component that has not yet been added to the page. This can sometimes lead to an invalid or no localized resource returned. Make sure you are not calling Component#getString() inside your Component's constructor. Offending component: [MarkupContainer [Component id = panel]]

This happens for every perspective, when the document editor is opened, etc.

Steps to reproduce:
1. tail the hippo-cms.log file
2. login to the CMS (either as admin, editor, or author; does not matter)

Expected behavior: no warning are logged
Actual behavior: three of the same warnings are logged (identical to the one above).