Ok, first download the attached file. It's generic AT&T service books.
Then on your computer go to C:\ProgramFiles\CommonFiles\ResearchInMotion\Share d\LoaderFiles\OS version\Java. Select File>create new folder and name is ATT. Then find the .cod named net_rim_bb_browser_dameon and click and drag the module into the new folder you just made.
Put in the AT&T sim card>plug in device>open DM>Apploader>Add/remove programs and step your way through. It will then remove the net_rim_bb_browser_dameon module.
Now Open the Dm again>Backup/restore>Advanced. On the right will be the Storms info and service books, etc. On the box to the left select file>open and select the file you downloaded. Once it's in the box on the left, click once to highlight, then click the bottom arrow(which moves what's in the left box to the right). Then go back to main menu of DM.
Go back to C:\ProgramFiles\CommonFiles\ResearchInMotion\Share d\Loader\OS version\Java and go into the folder you created named ATT. Right click the module>Cut>Go back to main Java folder and paste it back.
Exit out. Plug in device>Open DM>apploader>add/remove> and step your way through. You will see net_rim_bb_browser_dameon.cod file being replaced.
Now go to AT&T BIS Page
log in and resend your service books. Then on your Storm go to Option>Advanced Options>TCP APN should say APN: wap.cingular Username:WAP@CINGULARGPS.COM Password: CINGULAR1
Sorry I didn't include screen shots, just don't have the time. But this will get what you want. however the Storm will not work on AT&T's 3G network.