Upgrading from 3.1.3 to 4.0.1

[the director]

Anyone know how to upgrade a jailbroken 3G iPhone from 3.1.3 to 4.0.1?

I've quite happily running the phone and all my apps on the earlier operating version and was also quite happy not to update the apps as they all seemed to work fine for my needs. However, I now have to update the os in order to allow the MobileMe calendar syncing to continue.

The problem is that iTunes would like to upgrade the os to a version beyond that which can then be jail broken i.e. 4.2 or something.

Any ideas anyone?

 

[Mikey]

and it don't half slow the phone down

 

[richie]

Just don't let Itunes upgrade/update it...

 

[Buttso]

Hi

I upgraded my wifes iPhone to 4.3.1 or 2.. cant remember 100%

you can use redsn0w (this is what I used)

http://blog.iphone-dev.org/

or spirit
http://spiritjb.com/

as the other comments mentioned.. NEVER EVER upgrade directly from iTunes

for the speed issue and memory, you can disable the "multitasking" option when flashing the firmware.. this can improve battery life.. at least it did with the wifes iPhone when I was dicking around with it...

hope this helps...