|Hmmm, I'm assuming you mean that his clothes aren't staying dry, not the covers? It's totally normal for covers to feel damp/wet on the inside, especially after an overnight diaper.
I'm assuming however that you mean that it's the clothing that are getting wet so I'll go with that. First, for the smelliness... Do you store used covers in the diaper pail? If so consider stopping. Prolonged contact with dirty diapers can really set in odors and make them difficult to remove. If you must you can still wash the covers with your diapers (although it might help the odor not to) but at least store them seperatly till wash day. Do you handwash or wash in the machine? If you handwash try machine washing at least every so often, many find that as baby gets older handwashing just doesn't cut it (or maybe at least try a stronger soap if you're not already - maybe a laundry detergent bar like Sunlight). Also try soaking for a few hours (or overnight) in warm water and baking soda.
For the leaks maybe consider that it's time to move up a size. Many find that even though the covers still technically fit that leaks stop when they move up a size. Is the diaper completly soaked when the leaks happen? You mention that they leak when they've been peed in only a couple of times. A couple of urinations may well be enough to completly fill the diaper (especially for an older baby) so it could be that he needs changing more often. If a diaper is totally saturated and can't absorb anymore then there's just nothing a cover can do. Is the leak coming literally through the middle of the cover or leaking out the leg/waist holes? Maybe try to find out if there's a small pinhole in the cover(s) by putting a clean/wet towel or diaper inside the cover, closing it and pressing gently all over. If wetness comes through then you either have a pinhole or the cover just isn't waterproof anymore. If either is the case then there's not much to be done. You could always try using them when you know you can change often and/or maybe when not wearing clothing over top - this way at least your little can run/crawl around without making a mess and yet you won't have wet clothing to deal with. Assuming they were new a year ago I would still expect them to be working just fine (based on my experience and what I've seen on the boards covers usually last several years) but technically ME only guarantees them for 6 months -so it's not impossible that they're just expired and you need new ones.
Karen. PS - I hope my post isn't too hard to read - the board still isn't allowing paragraphs for some reason.