After checking out the SVN repository, i found that the TortoiseSVN icon overlay does not work.
2. If that doesn’t fixed the problem, probably the reason is because of the limited number of overlay types. For Vista 32-bit, it could support 15 overlay types, whereas Windows 7 64-bit only supports 11.
4. Go to
HKEY_LOCAL_MACHINE - SOFTWARE - Microsoft - Windows - CurrentVersion - Explorer - ShellIconOverlayIdentifiers
6. Reboot and check!