Admin Central's menu shows hardcoded label 'Inbox' instead of localized version. It is due wrong key in bootstrap repository file. Here is an trivial patch to fix it:

— ./magnolia-module-workflow/src/main/resources/mgnl-bootstrap/workflow/config.modules.adminInterface.config.menu.inbox.xml.orig Tue Sep 12 09:18:27 2006
+++ ./magnolia-module-workflow/src/main/resources/mgnl-bootstrap/workflow/config.modules.adminInterface.config.menu.inbox.xml Wed Apr 4 08:52:43 2007
@@ -23,7 +23,7 @@
<sv:value>MgnlAdminCentral.showContent('/.magnolia/pages/inbox.html', false, false)</sv:value>
</sv:property>
<sv:property sv:name="label" sv:type="String">

• <sv:value>Inbox</sv:value>
  + <sv:value>menu.inbox</sv:value>
  </sv:property>
  <sv:node sv:name="MetaData">
  <sv:property sv:name="jcr:primaryType" sv:type="Name">

Note that localized menu labels are already in (magnolia-module-admininterface\src\main\resources\info\magnolia\module\admininterface\messages_*.properties) - yes they are part of admininterface (not of workflow)).