Well, I checked in the game, and... good news, I was able to get 1360x768 to work, so we at least know it's possible.
1360x768 does not show up in the in-game options menu, true enough. But when I edited the WEngine.ini file for 1360x768, the game would start and play fine at that resolution.
1. Maybe the wrong WEngine.ini file was being edited.
I'm on Windows XP 32bit, so the path to the ini for me is this:
C:Documents and Settings
My DocumentsWolverineWGameConfigWEngine.ini
2. Are you totally, totally sure 1360x768 shows up in your windows settings resolution menu?
3. What kind of display are you playing on? Maybe the OSD is incorrectly reporting 1360x768 to be 720p.
Here's a screenshot: