Are you connected to an "L" port or a "C" port on the Invacom? The L is for Linear satellites and the C is for Circular satellites. The sats you mention, are Linear sats, however there is a Circular sat at 91 degrees, where G11 is located. It's one of the Nimiq satellites, but you shouldn't get anything from it if you're set for 10750 on the L.O. frequency?
If you are using a Diseqc Switch, be sure you have the receiver set for the correct port number, for L and for C?
Edit: should have read entire thread before responding, I see my responce is moot, after reading your post #3. Sorry about that, just ignore this......