It sounds like you are using a windows machine, but it would be helpful to know what version of windows you are using.
Are you using the built-in iSCSI initiator or something else?
If you are using the built-in iSCSI initiator then it will be helpful to know which version so the solution is easier to write down.
With that being said it seems like you never configured the initiator to use a password to connect to the SAN.
I can give better directions once I know the answers to the questions I asked above.