Do you have an adware system protecting you? If not, that could be the problem. Adaware is a good one and free to download. Also, the latest Norton anti virus system includes zapping these (sometimes very nasty) adware thingees (they didn't a few years ago).
never been on the net on my phone or sent an email on it orange dont seem to know either, keeps saying not enough space for multimedia (which i never use anyway) :(