Internet on my itouch :(

I just got it like a week ago and eveything was working perfectly until now. It says that I am connected to the wifi but then when I try going to facebook, myspace, or YouTube using the safari, I can't log in even though I am connected to the wifi. I am able to go to the website but then I can't log in. For example when I go to facebook, it will load me to the site but then that would be it. There is this loading thing in the middle and that would just be it. Same as for myspace, I would go to the website but then I can't log in. The weird part is if I try using the normal site just like the one u would see on the computer, it works but then i can't clear my status if I want to and can't post stuff. I am able to go to facebook using the app ok but then when I get notifications and I am refreshing it, I can't see the comments on the post. I have to log off and log back in to see it. Can someone help me? Please and thank you