My car will bog/hesistate hard when cold in the lower rpm. After the car warms up it runs much better but will bog a slight bit, i played with the dist., with it advanced all teh car the car still runs like crap when cold, but fine when warmed up.

 

Mine does the same thing. I don't think its too much of a burden, just let it warm up a little.

As far as what causes the hestitation, I don't know. Maybe someone can help out.