Check your glasses, see the article on glass care on this site. Carlsberg is a proper bottom fermented beer that does not have co2 artificially injected into it. Also it does not have head retention agents either, so what you have is a very good lager that may not be quite so lively as some of the other popular products. All lagers need the correct balance pressures for best dispense so put in a non urgent call to your supplier and have him check things out.
