Like many others, I use Ankh and TortoiseSVN. However, once I upgraded TortoiseSVN to 1.6.x from 1.5.y, all my files in Visual Studio were marked as "New".
The solution, as I mention in this StackOverflow posting, is to update to a later "daily" build of Ankh. This is because the working copy versions were updated to 1.6, but the latest stable version of Ankh was still compiled for version 1.5. The daily build "recognized" the newer version, and thus the files were marked appropriately.
I have had no problems with the daily build of Ankh that I installed (specific version is AnkhSvn-Daily-2.1.6649.29.msi).
Hope this helps!