My intermittent wipers on my '04 S were not working for a couple weeks last fall, but they magically started working again on their own. That happens periodically with my stereo, too. Sorry I can't help. I didn't have the problem with the wipers not returning to the down position, though.
Same thing happened to the wipers on my '02. I ignored it for a bit as it was only the intermittent wipe and an intermittent problem....then it spread to ALL wiper modes... which was very bad when driving at speed in the rain as it kept stopping the blades in mid-swipe! (and of course you only find this out when you need the damn things!) I found adjusting the telescopic wheel (just pulling it in and out once) often, but not always, got them going again though that was, obviously, a temporary fix.
After that I took it to the dealer and they replaced the switch (in the steering column at the end of the stalk) under warranty. Interestingly, they said it's not the first one they've replaced either...may be worth getting checked if you're still in your 4 year warranty...if not and you decide to leave it just remember that it might get more serious.... like mine!