First, it sounds as if you didn't get the head gasket installed correctly the first time. Typical problems are uneven head bolt torques, or a bit of crud under the new gasket when you installed it. However if it hasn't blown again it sounds like it is fine this time.
Hard cold starting but easy hot starting is usually due to the choke or primer not operating correctly. If I recall correctly in this case you are talking about a Powertorque with an evil plastic carburetor. I don't do those. However, did you prime it correctly before you tried to start it?
