Specs:
ATI Radeon HD 5700
Intel i7 2.93GHz
8GB DDR3
I have the newest drivers. I have tried other drivers. This does not fix it. I'm running at 1920x1080. I have tried other resolutions, including both 4:3 ratio as well as other wide screens. This does not fix it. I have tried using the in game AA settings as well as setting AA through CCC, to include various levels as well as types of AA. This does not fix it. Turned Vsync on and off, no difference. I've tried changing many things in the ini to no effect. I toyed around with the idea of running it in window that is maximized to the screen but just barely off the edge top and left to hide the bright line, but AA does not work when in a window, so this is not really a solution. I edited the sky texture to make the edge lines black and this only caused a black line through the middle of my sky.
I have spent quite a while browsing the net and the forums to try and find a solution to this. I have found a few threads where people seem to be referencing this issue, but no one has a solution. Inevitably a few people stop by to make some comment about drivers, but no real solution. I'm aware I could play without AA, but that is not the point. Getting it to look as good as possible is half the fun of Oblivion for me. Thanks for taking the time to read my post.