Having the same issues - the TV is connected to my network, but not the internet. This has been happening for a couple months now. Very frustrating!!! ISP has sent two techinicians out and there is absolutely no problem with the internet...all other devices connect via wifi without issue.
By the number of posts on this and other message boards, it is glaringly evident there exists a real problem! Samsung needs to find a solution to the flaw within their hardware...doing a factory reset or paying out of pocket for a "technician" is not a viable solution.