Some people just don't read the original post and just posting unrelated problem solutions!
I have the exact same problem as the guy who started this thread. Some water came onto the connector, it corroded over time and now im stuck with a constant stream of pop-ups which tell me this accesoiry isn't optimized for use with this iPhone. Now i can live with these messages, but the worst part is that i keep missing my calls because the $@^& thing won't make any sound!
If you are at the same stadium as me please stop with trying to dry the iphone with rice, hairdryers or other junk. The damage is already done and we are trying to find out how to reverse it.
I've been looking over the internet and tried some methods of getting these green eroded contacts back to work. Corroded contacts are allergic to white vinegar. But the problem with white vinegar is that it is a fluid which won't dry quick enough to not activate the white indicators in the iPhone.
So i'm afraid this won't work if you still have the iPhone under warranty. < Waterdamage is outside warranty, also opening the iPhone! I want to do this inside my warranty!
Alcohol is a substance that WILL dry quick enough without activating the indicators but it won't (or hardly) clean eroded contacts.
I've also tried scraping the contacts with a fine needle. Some greenisch gunk came loose but it didn't do the tricky.
So i'm still stuck with the pop-ups, but my quest won't be over and i will keep trying to find a sollution to this problem. When i find it i'll update this post!
UPDATE: Well, the new IOS 5.0.1 update seems to get rid of the pop-up. Still no sound though. :)
UPDATE 2: Allright, i've got the sound working again. And here's the trick.
To clean the contacts without opening or activating the waterdetectors you need a small pipe-cleaning stick. Like this: http://tinyurl.com/85hvy2w They come in two variants. Brushy like a toothbrush and a softer one with some kind of cloth. I used the cloth-one.
First apply some alcohol to get most of the junk out. I've dipped the small end of the stick into a 70% alcohol which you can buy at your local farmacist.
Brush the pipe-cleaner strongly at the side which holds the connectors. The other side (the smaller one) doesnt has connectors. And this way you avoid hitting the water-detector-thingy.
In my case the pipecleaner turned a little black. Indicating there was some smudge in the connectors.
Repeat this till you get all the black smudge out.
Then get some White Vinegar (just in case, i don't know this helps, it's said to remove corrosion. ) and repeat the first step. Don't be afraid to bend the connector its pretty firm and can take a lot of force.
Then when you're sure you had every connector het a hairdryer and blow the connector dry.
This way we are sure you won't activate the waterstamp-how-do-you-call-it-thingy.
For the last step, get some contactfluid. Spray it on the pipe-cleaner and brush it firmly alongside the connectors. Contact-fluid cleans and protects your contacts against further corrosion. When some of the cloth comes of the pipe-cleaner; take a toothbrush and brush the connector.
Dry the connector with the hairdryer and it should be fixed!
If not, repeat these steps all over. It can take a while but it saves you a lot of money!
I had two connecters corroded looking all greenisch, but after this treatment i've got them all gold again. Took me 30 minutes and left the iPhone on the entire process.
Hope it works for others.