I had trouble with the Gym at Sunyshore City, for a while. I ended up having to train a few levels because I both could not type trump (had no Ground types) and I think I was low/mid 40's, when I got there. Although I don't know why I had such trouble, because ever since, I've been able to get by, no problem... o.o
Oh; I tend to still have trouble against Maylene(?). Her Lucario always seems to do a number on my Pokemon and half the time, she gets the Stat Boosts... completely nullifying any advantage a resistance would have given... -.-;;
The puzzles were not hard at all.