Ok Ignore Z's reply.
it could be a number of things.
1. with IE open click on file at top left and make sure there is no tick next to the word "work offline" if there is click on it to remove it , then restart IE.
2. Have a look around the internet options and the connections tab if you on a home internet connection makre sure you DONT have the proxy box ticked.
Oracle9I
October 2008