Ipad messages "Safari cannot open the page because the server cannot be found"
I recently updated my Ipad 2 to ios 5. Since then I get frequent but intermittant messages from safari and other apps that say "Safari cannot open the page because the server cannot be found" or something similar. The web sites I am trying to access are all available on my desktop. I need some help in solving this problem as the Ipad is not usable as it is. My wireless network is WAP. Clearing the cache and history sometimes helps but not alway.
iPad 2, iOS 5, Tried other browsers same result