From: mikkelhaaheim@gmail.com   
      
   From your description, it sounds like you were doing your calculations based   
   on either payload mass or gross launch mass only. You need to average out the   
   thrust applied to gross mass and the thrust applied to deadweight mass before   
   gong on to apply burn    
   time.   
   Another thing to consider is the effect of atmospheric drag as well as gravity   
   drag. The first can be largely ignored if you are calculating orbit to orbit   
   missions. The second can not. If your rate of  acceleration is very low, the   
   required delta v will    
   be significantly higher. You must subtract the gravitational force of the   
   planet you are leaving, which is still actually quite high, even in orbit.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)