mysql replication issues

[Jamesk5]

I've got replication working on two machines, both running Debian (etch) and the latest version of mySQL-server-5.0, but I've got an issue with the slave.
If the machine goes down, the slave 'feature' of mysql doesn't seem to automatically turn its self on - not sure why. I've followed the mySQL docs on replication.
Also, when I run the 'start slave' command on the slave, it doesn't go and automatically carry out any changes that have been done on the master since the slave went down.

Any suggestions will be appreciated,
James