Accessing variables in another script using GetComponent()

I've just run across a showstopper when I built a webplayer version of my game, oh dear=S At a certain point in my game I initiate a timer on a script attached to my player character that, when it runs out, sets a variable on a script attached to an npc to true, which causes it to move along it's waypoints etc.

It works fine in the editor, hence why I didn't see any problem previously, but it doesn't work in a webplayer or a standalone app. I tested using one of my guiText functions to show a message after the variable has been set - I never see this message outside the Editor so it looks like the variable is not being set. If I set the isMoving variable to true initially, the npc moves as expected, so the problem must lie with the way I am accessing the variable on the other script.

My code at the moment is below (note I have commented out the line that finds the npc gameobject since I have moved this into the Start() function:

if(sinkTimer > cleanerResponseTime){

 // cleaner = GameObject.Find("cleaner");
 otherscript = cleaner.GetComponent("wp_scriptNew1"); 
 otherscript.isMoving = true;

 if(otherscript.isMoving){
     TextHints.message = "isMoving is true";
     TextHints.textOn = true;
 }

I should point out that multiple npcs have this script attached so I cannot use static variables. I tried to use the method described in the docs here for exposing references to other objects, but I get a warning that a local variable called otherscript already exists. That's true since the code that initiates the timer stores its reference to another script in a variable called otherscript too. However, I have not declared these variables at the top of my script so I assumed they could be treated as temporary variables? (like when using 'i' in a for loop for example).

Renaming one of them and using the code from the docs allows it to work, so:

var otherscript2 : wp_scriptNew1;

     otherscript2.isMoving = true;

     if(otherscript2.isMoving){
         TextHints.message = "isMoving is true";
         TextHints.textOn = true;
     }
 }

But I still don't understand why using GetComponent didn't work, since the other piece of code which still uses it successfully sets a boolean to start the timer above in the first place.