So you paired the two devices, you used the "ATT Internet" connection on your N810, it claims a successful connection on the tablet, yet the icon on the phone is red and you have no access to the web from your N810? What data plan do you have tied to your wireless line? You should be able to get on with any MediaNet feature added to your line.

I will have access to the A737 on ATT when I get home tonight, so I can test and confirm my experience if you'd like. I currently use ATT with my SGH-D807 and have had great success with my N800+OS2008. I couldn't do squat with my 770+OS2007HE and the exact same phone, no matter what I tried for DUN strings/configs. Very annoying, but it just makes the N800 that much more of a prized purchase.