I assume I am not the only one out there who uses Tortoise SVN and AnkhSVN for source control with Visual Studio.  After the most recent update by Tortoise SVN, compatibility between the two is lost.  The Tortoise SVN 1.6.0 release notes say "The working copy format has been upgraded. This means that 1.5 and older Subversion clients will not be able to work with working copies produced by Subversion/TortoiseSVN 1.6.".  Until an update to AnkhSVN is released the is compatibile 1.6, compatibility between the 2 will be lost. 

This was important to me so I reverted back to Tortoise SVN 1.5.9 until this AnkhSVN is updated.  This was easy enough to see once I read the release notes but a little frustrating to figure out since I didn't read the release notes up front.