Unfortunatly we can't close his door because he is scared to sleep with it closed (or to have it closed ever, really).
The cat is probably about 8 years old. However, seeing that is pretty healthy and thin we suspect he's going to keep on ticking. Or in this case, meowing...
Thanks for the advice.
We have a pretty severe problem with one of our cats: it is keeping us up at night. When we bought our first house we started putting the cats in a cat room at night. We did this for a number of reasons, including so that the cat that is a problem wouldn't wake our young son up at 5am anymore...