Logon prompt when clicking on Save as... on a document through KM iView

Hello,

We are using NW04s SP9.

I have created a KM iView which points to a certain KM folder which resides under the standard /documents folder of the portal.

The problem is this: When users open a certain document through this KM iView, for example an excel or word file, it is being opened but when they select the Save as... option it prompts for User ID and password.

How can I supress this and allow the users to save the documents without being promted?