Link: http://serverfault.com/questions/72561/64-bit-tortoisesvn-on-windows-7-says-file-or-directory-is-corrupted-and-unreadab

For quite a while now I've been having issues with TortoiseSVN reporting that files were corrupt while updating and submitting.  After my working copy became corrupt, yet again, I decided to do some research and turned up a solution to the problem.  Apparently there is a bug, introduced in Windows 7, with the MoveFileEx command that TortoiseSVN uses quite frequently.  The fix will be included with Windows 7 SP1, due out sometime next year, but you can get the hotfix right now at the link below.

Hotfix:  http://support.microsoft.com/kb/982927/