Questions on Kantian Ethics

1. I decide to have dinner at 6 pm. The maxim of my action is 'I eat dinner at 6 pm' The universalization of this maxim is 'Everyone eats dinner at 6 pm' If this was a law then sick people would die, fires would rage untended, etc. I conclude that I can't eat dinner at 6 (I also conclude that I can't eat dinner at any time, and I die - which is sad!) Is this a problem for Kant's ethics or have I applied the rules incorrectly?
 
2. Suppose you want to decide whether to cheat on an exam. How would you apply Kantian principles in reasoning about this? Consider both versions of his Categorical Imperative, i.e. Universal Law and Principle of Ends.