Q: Iphone 3G slow after update to IOS4

It is highly unlikely that Apple is going to issue a fix. They have pretty much made it clear that the 3G is no longer supported, since they stopped pushing the updates out to it after 4.2.1. I feel your pain. I had a 3G until yesterday. I can't afford to buy an iPhone 4 or the new iPhone when it is released, so I bought a refurbished 3GS (my contract was up for renewal). It is SO much better than the 3G. When I tried iOS 4 on my 3G, I downgraded to 3.1.3 and it helped tremendously. I know that solution won't work for everyone, however. 

Scratch my last post. I decided to return the 3GS to the AT&T store and order a refurb iPhone 4 (but I can't order for 72 hours since my return is being processed through the AT&T system). I am using my old 3G again. I had put iOS 4 on it because I anticipated either selling it to buymytronics.com or on eBay. It is pretty slow, especially now that I've used a 3GS and saw the speed difference. I've said this before and I will say it again: Apple should have made 3.1.3 the end of the line for the 3G. iOS 4 is terrible, terrible, terrible on a 3G, at least in my experience and the experience of many others on this forum.

Leann,

That's the reason why I west back to' 3.1.3. End of the story, no more slow iPhone, everything is fine now, and I'm enjoying my 3G again.

Sorry, typo: "went back".

I tried all the methods described in this thread but none was successful. I cannot imagine how they can just ignore so many people complaning about their slow iphone 3G's. Thought will update to 4G but was not interested when Jobs said we had to hold it in a certain way ... dumped my iphone and went to WP7.. never gonna get an iphone again...

The areas I live and travel all have 4G support.  These 3G phones are a joke... all of them.  3G is just plain slow, and many apps are more advanced then 3G can support in my opinion.

Bottomline, Verizon smokes what ATT&T has to offer, and unless the iPhone 5 really steps it up, the Droid is looking better every day.

I can't wait until my SA contract with ATT&T is over and I can finally dump this phone and ATT&T. 

At least you haven't gotten this incredibly condescending, unhelpful response yet -

"Sorry, but downgrading the OS is considered an unauthorized modification. You have voided any warranty and Apple Care that you had and can't be supported here."

How is that condescending? It's a fact. Apple doesn't support downgrading the iPhone. It does void the warranty and Apple Care.

Try clearing temporary files to do this go to settings, go to the safari tab and clear history cookies and cache. This will improve the speed tremendously

For me there is only one answer. Apple needs to replace our iPhone. Wait until CNBC gets a hold of this.

You'll be waiting a long time. Like I've said before, it's a three-year-old phone.

pretty sure they do it so you upgrade, probably won't be getting another iphone or apple product. On top of all the walled garden/must ask uncle apple for approval to do anything, these updates have just made it slow and laggy. Same on my friends phone.

amen

iOS 4 doesn't give your iPhone many new features and makes it slower. What I would recommend is upgrading to iOS 5 which gives you many new features and makes your iPhone run like new.

David,

iOS5 can't run on a 3G....