Can't mount objects with a class?

I'm trying to mount a text object I made set with a class I wrote allowing it to accept input events like mouseover and clicks. But when I try to mount my object to a staticSprite, I get an error:

"Namespace::unlinkClass - cannot unlink namespace parent linkage for ObjectListText for t2dStaticSprite.
Error: cannot change namespace parent linkage of ObjectListText from t2dStaticSprite to t2dTextObject."

What am I doing wrong? All I'm doing is mounting a textObject to a sprite.. nothing fancy. It just happens to have a class so it can accept input.

Here's a small example of what I'm doing:

%t = new t2dTextObject()  {    
             class =  "ObjectListText";   // my class 
             scenegraph = %this.owner.scenegraph ; 
             layer = %this.owner.layer;   
             canSaveDynamicFields = "1";
             useMouseEvents  = "1";
             BlendingEnabled = "1";  
           };     
           %t.mountToLinkpoint(  %this.option[%i]  , 1, 0, 0, 1, 1, 1   );

Any tips or workarounds would be much appreciated.