gift on shabbat

Question

Hi Rabbi, Is one allowed to give a gift on Shabbat? My family has a tradition of celebrating our birthdays at the Friday night or Saturday afternoon table. We give them birthday boy/girl greeting cards and a gift. The gift is usually anything from clothing to a cd player. A cake is brought out during dessert (no candles of course) and everyone is happy. I am not sure but I think that you have stated in the past that there is a problem with the exchange of ownership on Shabbat. Thank you for your help. Jomiz