Skype directX problems?

i have a HP Pavilion dv 7 with hp truevision webcam and directx 11. when i go to video chat on skype with someone it say it cant get a valid directX connection. why is that? it did it before and then i downloaded service pack one and it stopped. now it has come back. i can hear the people pn the other side and they can hear me, but i cant see them i can give you more details if you need then.