Flash CS3 Component mxi/mxp

Can anyone point to me some information regarding the use of MXI/MXP files with Flash CS3?

I’m using the same technique as I used with Flash 8 to create components ( SWC ) and package them to an MXP file so they can be installed via the Extension Manager. However, even though the Extension Manager is telling me that the install was successful ( I do have Flash CS3 selected ) there is no sign of the component in the Components panel in Flash even after restarting it.

Any ideas?