Multiple feedbacks received from same buyers/sellers will not be taken into account. Those feedbacks will be counted as a single feedback.
For example, if you bought a dvd player from sellerA, he left a positive feedback for you, again you bought an MP3 player from sellerA at a later date, and he left a positive feedback for you. Total positive feedbacks received from seller A: 2. They will be considered as a single feedback.
Hope this would help.