Property IsLocked is not available - La proprietà IsLocked non è disponibile

Sometimes after rebooting the machine with sql server 2005 standars installed I cannot connect using the sa user and I receive an error when I try to manage the user:

"La proprietà IsLocked non è disponibile per Account di accesso 'sa'"

Or, in english:

Property IsLocked is not available for Login '[sa]'. This property may not exist for this object, or may not be retrievable due to insufficient access rights. (Microsoft.SqlServer.Smo)

The only solution is to unlock the sa user using the command:

alter login sa

with password = 'yourpwd' unlock,

check_policy = off,

check_expiration = off

After this all works ok.

For details look at http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=1673143&SiteID=1

Hope it helps,

Matteo