[MlMt] scripts/rules not taking effect...?

[Seebs]

So I have some rules, which appear to work. And I have other rules, 
which... don't seem to. And I am not sure what I'm missing. But I 
vaguely recall there having been an option for turning on logging so I 
could see more information about rules.

As an example, consider the script MoveMlmt.mmCommand:

{
         name    = 'Move Mlmt';
         events  = ( 'account.synchronized' );
         select  = "subject =[c] '[MlMt]'";
         actions = ( { type = moveMessage; mailbox = mlmt; },
           { type = changeFlags; enable = ( '\\Seen' ); disable = ( ); 
},
           );
}

The intent is to move things from this list automatically into a 
mailbox,
and mark them as seen. (Okay, maybe not a great plan, given that I 
presumably want to see responses to this, but it's a good example.)

Anything obvious to explain why this wouldn't work, when at least some 
other rules appear to be working?

-s