You do not need a new viewing card. You can use your exisiting card, but you (or your agent) will need to contact sky with all the details for the sky account and sky+ receiver to get them to pair your existing card with the sky+ receiver. You will have to remind the sky staff that it is a sky+ receiver and ensure they activate the recording functions. until this "pairing" takes place you will not have access to the sky+ recording functions - but you will be able to watch your channels!
the activation can be either instant or take a few hours!!
Hope this helps.