Farmville gifts disappearing from the requests part before they have been accepted.?

Why are my Farmville gifts disappearing from my requests box, I go and accept one when I have many eg 50+ and i go back to accept the rest one by one and there gone. i cant understand why they are disappearing. i have had this a few times now and am getting really annoyed with losing them as the gifts are things that i need for my farm. is anyone else having this problem or do you know how i could try to resolve it or what it is that is doing it orr even anything would help please. thank you :) xxx