Okay. First, you need to send the robot up the shaft and open gatenbrinks door (And there's not another dorr behind it
and then you can either go in the new part that it shows up, which I don't have any hints for at the moment, because everything I've done there is pretty easy. But you can go to the Kings chamber. And if you've been in there before you'll see that behind the coffin there is an opening. Go through it. You'll be in another chamber, and I won't tell you what's in there, but you can't really do anything but look aruond, or, so it appears. Standing in the same place as you were when you entered the room the first time, move the mouse around until you have the forward arrow and press it. You should go under the bed in the middle of the room. If you don't, return to starting position and try a different spot with the arrow. It took me forever to figur out there were more chambers. What actually gave it away was when I read that the annex in Tutankhamen's tomb was found under one of the gilt couches
P.S. I haven't figured out what the door is at the Sphinx yet.