If your package starts failing due to a connection failure and you are using
SQL Server security, check to see if the password is present in the connection.
If there are no asterisks in the password box, and the password is not blank,
you will need to enter the password again. Before closing the connection dialog,
click Advanced and check that the "Persist Security Info" property is true (-1 or 1).
Sometimes for no apparent reason "Persist Security Info" will be set to false (0).
In this case the password is not saved when you close the connection, and you will
get a connection failure during execution.