Common Interface question

[avalon65]

On my Gigablue TV box behind the drop down cover, there are x1 Card Reader and x2 Common Interface slots.
I have a Virgin Media TV card and I have connected the Virgin cable to the cable tv connection on the back of the box.
I have enabled Virgin TV on the list of Providers , but in the Common Interface section there is only 1 slot and it says no module found

Now my questions are:which of the slots do I use for the virgin card, and do I have to download any kind of plugin or do anything else.

Thanks