Running SVN (or TortoiseSVN) on 64-bit Windows 7 can often cause errors reading "The file or directory is corrupted and unreadable. Please run the Chkdsk utility." This is caused by a known bug in the Windows 7 NTFS file system. A few months ago when I first researched this problem there were supposed reports that disabling indexing on the folder or disabling antivirus would fix this problem. This was not the case and I had to deal with the issue for over a year.
Microsoft plans to fix this in Windows 7 Service Pack 1. But there is a hotfix available.
This is a known regression in Windows 7 in the NTFS file system. It occurs when doing a superseding rename over a file that has an atomic oplock on it (atomic oplocks are a new feature in Windows 7). The indexer uses atomic oplocks which is why it helped when you disabled the indexer. Explorer also uses atomic oplocks which is why you are still seeing the issue. When this occurs STATUS_FILE_CORRUPT is incorrectly returned and the volume is marked "dirty" which is a signal to the system that chkdsk needs to be run. No actual corruption has occurred. - Via (Microsoft TechNet) Via (Subversion Community Beta)