Hey mate
Reason you kept getting disconnected was you where trying to join with the name "Kriller".
When we role-play we do it with as much realism as possible, so players that connect without a name which follows the format "Firstname_Lastname" are kicked immediately.
Change your name to something like John_Smith for example, and you won’t get kicked. I’m sure any of us on either the Walters or Lords of RP servers will be more than happy to help you figure stuff out if you’re new to RP in SA-MP.
EDIT: Also the /register bit means you need to type /register YOURPASSWORD, then /login YOURPASSWORD.- Tom Walters (Admin on Walters RP Server)