If you are not able to disconnect and reconnect quickly or attempt to use an invalid password - you may have to wait a minute before reconnecting. This can be adjusted through a registry modification.
Registry setting for timeouts
The WebClient service maintains a list of non-DAV servers (negative cache) that have been contacted in the last 60 seconds. If the server is found in this list, a fail is returned immediately without going on the network. The time a server remains in this list can be modified by changing the value of the ServerNotFoundCacheLifeTimeInSec registry entry.
Note If the
registry entry does not exist, create the entry.
Value: Default 60 (Decimal)
No maxium and no minimum value
We recommend setting this to 5 seconds.
This is discussed furhter in http://support.microsoft.com/kb/832161