Isuzu Repair: 2000 Amigo, upper intake manifold, head gasket

Question
my amigo over heated back in April. I was told that that every thing was cooked. I had the thermostat replaced, radiator, water pump and they removed the head and had it machined, replaced the head gasket and a pressure tested the cooling system. All that at 74,080 miles. Now at 76,135 it started to over heat, so I brought it back the repair shop, they couldn't find anything wrong just needed more antifreeze. I have put antifreeze in it several times now. I can't find any leaks and theres no spots on my driveway. Theres no antifreeze in my oil, but I smell it burning, any ideas on what may be the problem.

Answer
Yes I do Terry:) Well first of all they have a HORRIBLE problem of having the bypass hoses leak that run underneath the  upper/intake manifold. If you get a flashlight and look REAL close I bet you will find a  small puddle of antifreeze. Also have your system pressure checked and where the leak is you will be able to hear a hissing or see actual anti-freeze dribbling out okay? Let me know if you need anything else please Terry;)