Variable uses an Automation type not supported in JScript

I am creating an instance of a third party dll at client side using javascript. So far every thing works well. Even the properties and methods of this object showup when I keyin the object name followed by a '.'
I am also able to retrieve well the values that the properties of this object are holding.
But when I try executing it's methods, I am encountering the following problem.

Microsoft JScript runtime error: Variable uses an Automation type not supported in JScript

The particular method that I am invoking is probably returning a Long value.

Somebody please tell me why this happens, and how I can over come this.
I am using IE 6.0.2800.1106 (SP1,Q810847)

Regards

Suhaib

Can you post your code so we can take a look at this?

Fine.
Here is the code snippet. I get error in the second line

var CScan = new ActiveXObject("SCANW.SLibEx");
var ret = CScan.InitLibrary('<license_key>');

Just to reiterate - I am able to access the properies of CScan. It is only while accessing certain methods that I encounter this problem.
The InitLibrary method seems to be returning a long value.

Thanks in advance.

Regards

Suhaib