What version of Vault are you using?
Have you tried closing your client/Visual Studio, renaming your client-side cache file and restarting IIS?
You can reset the cache with the following steps: Find the path %USERPROFILE%\Local Settings\Application Data\SourceGear\Vault_1 and rename the entire Vault_1 folder. Reset your working folders and try the Get again.
If you need to presever working folder settings, see this:
http://support.sourcegear.com/viewtopic ... 13&t=11513
Failed to get latest in Windows7
Moderator: SourceGear
Re: Failed to get latest in Windows7
Linda Bauer
SourceGear
Technical Support Manager
SourceGear
Technical Support Manager