Coolant leaking from exhaust manifold gasket

I have a 1999 Olds Alero 2.4L with 68K miles. My 17 year old drives it to school and told me that the temp had gotten to HOT when driving to school. I added cooland and noticed a small drip from drivers side, but I suspected a leaking heater hose. When I got it home, I crawled under it and found that coolant was leaking from the drivers end of the exhaust manifold gasket. I noticed white exhaust smoke, and the engine sputters when started so I assumed that the head gasket was bad. I pulled the head and had it pressure tested and it checked out OK. I replaced the head gasket and exhause manifiold gasket and when I got it all back together and added coolant it STILL leaked out from the exhaust manifold gasket even before I started the engine. What on Earth am I missing here? Why is the coolant leaking out here? ANY help or suggestions will be graetly appreciated. George Peck