iPhone iOS4 Problem and Downgrade

Hi

Since I downloaded and installed iOS4 on Monday, I've had nothing but trouble with my phone (a 3G) - it seems really slow in responding to anything I do, such as clicking on Settings takes around 20 seconds to load, and clicking on the address bar in Safari takes a few clicks before it listens.

Firstly, is anyone else having these problems, and is there a way of fixing it? I've already restored the phone and reinstalled but still the same

And secondly, can I revert back to the last operating system, which had none of these problems, and if so, how?

Many thanks in advance

 

I was surprised it was available on 3G actually. Will have to wait until September until I can upgrade my phone, but can't be doing with this slow phone until then!

Surely there must be a way to downgrade?!