aoc.exe has no effect on this, thats for sure.
What you see is the black, semitransparent background tiles in the windows not being proberly defined or aligned at higher resolutions. I can think of three causes/solutions.
1. The background isn't tiled right in the appropriate .xml UI files.
Fix: Edit the appropriate UI .xml files to make sure it handles the tiling right at higher resolutions.
2. The background tile graphics having a different transparency at the edge.
Fix: Correct the graphic by either editing the textureatlas .dds file that holds the background or edit the textureatlas .gat definition file to exclude the edge of the background tile.
3. In some rare cases this can be caused by the graphic card driver.
Fix: Up or downgrade the driver to a different version. The newest isn't always the best. Or use one of the above solutions to fix it.
Hope it helps!