I had a problem similar to that.
In my macro that promoted my current driver-toon to master, I had
/jamba-team iammaster all
/jamba-follow master all
The problem went away when I rewrote it to
/jamba-team iammaster all
/jamba-follow strobeonme all

Things I would look at are:
Was the slave toon the previous master.
Does this only happen after combat, look at how you promote your driver to master.
Check if all your toons have, and are useing the same macros.
Check if you are useing the "all" arg in your macro.
Turn on channel debuggig. Look at whats happening when it happens.