No accessory = "This accessory is not optimized for this iPhone..."

Definitely software on mine. Wasn't resolved until I did the reset all settings.

I have had the same issue with my iphone 4 32g, i have a skull candy ipod dock that i have always used with my 3gs and as soon as i dock my new iphone 4 i loose all signal on my phone and the same error message pops up, it will allow me to play music i have stored on my phone but it will not let me have enough signal to stream any music through pandora/ pocket tunes, but as soon as i un dock it i instantly get all of my 3g signal back.

IPHONE 4
0S 4

I get this message all the time on my iPhone 4 also. Tried all sorts of restarts, nothing has worked. The music won't play because the phone thinks there is an accessory plugged in, even though nothing is plugged in!!!

Going to apple store to see what they say...

Ok so I was hoping for an update to fix my phone but still no updates but I noticed after I plugged into iTunes the message showed up more so I started wiggling the cable back & forth a couple of times & the problem is gone now. I used a toothbrush, blew out the bottom connector, even looked into the bottom & never saw anything before all this & the problem still persisted. So I'm not sure what happened but hopefully it stays this way.

Just installed Invisibleshield on my iPhone 4 and was getting bombarded by this pop up. I took some canned air to my 30 pin and let 'er rip after seeing others in this forum having success. I also cleaned it out as best as I could and when I turned it back on, no errors yet. It's been 10 minutes so fingers crossed.

Did the same, a lot of crap in there, no message yet. Looks like it was the fix for me. iPhone 3GS 16

This is going to be a stupid qu. just what to conform what i think it is. but sins it been like 2/3(iphone 2g) years sins i used an iphone. what does a hard reset do?

same issue here... accessory not optimised message. Cleaned the dock but still got the same message. Upgraded to os4 when it came out and the message persists even after I restored last night. I have not used any accessory (besides the charger). Just spoke to Apple, they suggest another restore and clean the connector, an appointment scheduled for tomorrow 😟

3gs 32gb iOS4

When I see that message, it has never been because of something plugged into the headphone jack, so I don't know what that would fix. But I think that may be on the right track, and combined with the gent who had funk in his connector you may have a solution at hand.

This is not so much addressed to the folks who are having actual compatibility issues with things like car audio systems, but to those of you with this message popping up randomly. Try plugging and unplugging the charging cable a few times. That might loosen things up and make the message go away. Similarly, if you have a can of compressed air, blow a few puffs around inside the dock connector opening. Maybe a stray bit of packing material or manufacturing residue came along with the phone as a bonus. Like Q-tips, I'm not advocating sticking anything in the opening, nor am I suggesting you ever put anything damp in there. But some air might loosen stuff up if there is, in fact, bonus material making contact in there.

You need to edit the plist inside the iPhone. I think this can only be done once you have root/su access to the device. ie : Jailbr....ahem.

Same here with the iPhone 4 and USA-Spec interface for Honda. Reset settings. I can play music now, but still no charging. What's going on? I would think that if there was a problem it would be the other way around, no sound but charging. Ugh.

Same scenario with Mrs 3GS. Solution, get a dry soft toothbrush and give that connector terminal a good de dust. Touch wood-last 24hrs have been ok.

A good clean to the port seem to have sorted it out for now at least 🙂

I have been getting the same message for about five days straight. I have noticed that it is draining the battery etc. I took it to the Apple store and they made me reset and restore phone as it was a new one. I did that last night and it did not work. They told me that i would have to bring back in and that they would look inside of it to see if i got it wet, which to my knowledge it has not been wet. I keep telling them my friends are having the same error message.

has anyone figured out a real solution yet, besides being told that i have to pay $199 to get a new phone.

And an answer is ...

Remove your screen protectors people. I'm currently in muggy muggy Cochin after coming from muggy muggy Mumbai .... yadayada
All of a sudden my 3GS started with the annoying messages.
As soon as I took the plastic screen protector off ... voila ... all gone