Heat kielbasa and 1/2 cup beer to boiling; reduce heat. Simmer uncovered 10 minutes; drain.
Toss cheeses, flour, mustard and pepper until cheese is coated. Rub bottom and side of 2-quart heavy saucepan or skillet with cut clove of garlic; add remaining beer. Heat over low heat until bubbles rise to surface.
Add cheese mixture, about 1 cup at a time and stirring after each addition, until cheese is melted and mixture is smooth. Stir in pepper sauce.
Remove to ceramic fondue dish; keep warm ovqr low heat. Spear kielbasa with long-handled forks; dip and swirl in fondue with stirring motion. If fondue becomes too thick, stir in additional heated beer.