My colleague and friend, Derek Martin of Slalom Consulting, just posted about a bug that we found with SharePoint 2010 and the Site Directory. 

The short story is when you enable the Site Directory and you are using SharePoint 2010 in Claims mode for your web apps (including the site that houses the site directory) Central Administration is in Classic mode (the default and recommended way) and actions that call a web service from CA that touch back to the Site Directory will fail with errors that do not give you any real clues as to what is going on.

The bug has been logged with Microsoft and we are awaiting the Product Team’s acceptance the they will fix this with a patch, service pack or QFE.  More when we hear it.

For the full details please check out Derek’s blog.