echo -a $active in an alias in the aliasses section and there you need the //.
You dont need // anywhere in script files, the // is only needed for commands entered the twin // informs mirc it should evaluate the line rather than treat it as litteral texts
ie: (from the command line)
/echo -a $me
$me
//echo -a $me
DaveC
& (called from an alias).....
example { echo -a $me }/example
DaveC
PS: on the original problem, The original code worked fine for me, so it must have been something else not listed that was jaming it.