I have had this problem several times in different network configurations. I'm not able to find the reason behind this. I have a small home network that has a server and this server distributes the internet between the clients. There is no problem with the server and I can browse any webpage and anything in those pages. However, as a client I have difficulty in submitting webpage forms or making google search and almost anything related to web forms has problems. Sometimes some pages do not show up at all. Some others can be opened but they're not complete. Cnn.com is an example. Anybody knows anything related to this matter?