One more thing. If you're using frozen seafood, be sure it's thawed out before you do the boil elsewise you will tend to overcook it and the temp of the boil will be taken too low.
Give this a look and see if it helps.
I've done several boils but we call them cajun boils around here.
Usually, we are cooking such a big batch that we have to cook the veggies seperate from the seafood and sausage. Also, I use andouille sausage rather than kielbasa as I think it lends a better flavor and I like to add cut up yellow onions and a lemon cut in half for flavor.
The main thing is to watch the seafood. When it floats it's done and don't overcook the spuds or they'll be mushie.
Good luck! This is making me hungry!
Speaking of Umm Umm Good, what will you Irishmen be having on St. Patrick's Day?