You can always try downgrading to 3.1.2, but if you donâ€™t have your 3GS 3.1.2 hashes on file with Cydia, youâ€™ll need to wait 3.1.3 out and see what happens with 4.0.
Hi all. I do not own an Ipad yet, but regarding iphone jailbreak I have done it a few times. If you upgraded to a 3.1.3 and all you want to do is jailbreak then the easiest way (works like a charm) is "SPIRIT"
1. connect your iphone
2. download spirit from Spirit
3. install the application
4. click on the only button available
5. in seconds your iphone will be jailbroken.