After upgrading my TortoiseSVN to the latest version from 1.6.12 and as well as my SilkSubversion.
I Checkout my project from svn again (not relate to the upgrade) and noticed that only the root directory contains the ".svn" folder.
Child folders doesn't contain the ".svn" folder any more.
After a lot of digging it came out that from version 1.7.X of tortoise and silk there won't be any child ".svn" folders (hidden) anymore. Only one folder in the root.
If you work in eclipse, you need to uninstall (unless till you read this they will upgrade it) the old subversion/svnkit/javahl plugins from it and install it again using this updated site
Hoped it helps,