CS-CART 3 password bug?

I am testing CS-CART 3 , i have problem in logging.

after some logins , my administrator account or customer account will go wrong.

My account and password is input correct, but the system says:

“The username or password you have entered is invalid. Please try again.”

So i check the the “cscart_users” table in the mysql database, i found the “salt” field have nothing.

and it will appear some characters like “fs&*eGVKPD” again after I recovered the password.

Is it a bug ?

cs-cart version: 3.0 rc4

php version: 5.3.8

mysql version: 5.5.21