Are you using certificates? If so you can reset them from the Console Tools CTRL + ALT + T then select "Time Configuration" just take the defaults to the end. If that does not work then reset the network settings again in Console by entering CTRL + ALT + I then go back and change your IP Address, Subnet, Gateway and DNS (If need be) by entering CTRL + ALT + N. Does this happen with other systems from the network as well?
OK, I got it. It was the installed certificate in IE from open-e. It seems that the old certificate was not the same as after the software update. But IE only showed that the page couldn't be found.... Very strange.
After the update, I have problems with the error message functionality. I can see that there are any messages, but when the message window opens, I can't see anything there.