If your ladyfingers are disintegrating on you, chances are you've soaked them in the coffee for too long. The ladyfingers just need to be dipped quickly (no longer than 5 seconds each) or else they will become too soft and mushy to work with. Next time you can also try allowing your coffee to come to room temperature before you start soaking. This will allow the coffee to absorb slower into the ladyfingers.