Vista 64 to XP SP2

Hi I have Vista 64 (Host Machine) XP SP2 (Client Machine). Now about two weeks go I had everything working just fine and i went and took a nap and woke up and loos the connection.

Heres the problem I can get XP too connect too the vista but i can;t get the vista too connect to XP.
I'am trying too map the network. When i try too connect vista to XP i get this error



ERROR:
The mapped network drive could noit be craeted becuase the following error has occurred.

Logon Failure: the user has not been granted the requested logon type at this comnputer

does anybody knowe what this means i get this when i connect Vista to XP.