those who using 3G 8gb with 3.1.2 firmware, hear me out

if jb with blackra1n, either in window or mac, ensure you put the blackra1n download to ur desktop, have your iTune running and disconnect iPhone before you run, else you will bump into problems
this method will not 100% jb ur phone although end of the day you able to dl cyndia but if you launch DiskAid, the root folder will still remain disable

another method is using Pwnage tool but please make sure you read the correct guide line for 3G and not 2G, I made the mistake and found out I was not able to follow the guideline half way through, here's the link for 3G
http://www.iclarified.com/entry/index.php?enid=4254

just need to make sure you have exit your iTune before you perform the below:
1. off the phone
2. press and hold power + home button for 10 sec
3. release the power button hold for another 5 second

then you will free your phone and able to access root folder in DiskAid.

Sharing this with you all so that you dont need to learn it the hard way. Cheers.

I have withness one Maxis set 3Gs 16GB with 3.1.2 firmware JB successfully using his Vista operating system. Is been working great ever since.

By the way, he JB using the blackra1n.

Guys, try this if you bump into problem with blackra1n
Download the file into ur desktop
Disable the auto sync with iTune when plug in the iPhone
Before run the blackra1n, connect the phone and allow itune to run at background
It really took him less than 1 min to complete the whole JB like how it describe.

Good luck.