French is indeed very difficult to learn, because of the pronounciation. The hardest part is of course comprehending the spoken word.
Comprehending written French is easy, while speaking it is pretty tough. But hearing and understanding, well, it takes a lot of immersion.
I happen to be reviewing my Capretz "French in Action" for a trip in June, and it's amazing to me how much I've forgotten (from disuse).
Tell me about it ! My Spanish has slided down since I stopped taking classes. Problem is, while I always found books I wanted to read in English, I almost never found good mystery novels or sci-fi in Spanish that made me want to keep practicing it just for the heck of it.