This table works with the assumption that the default 75° is optimal for screens with the 5:4 aspect ratio.
Use Fast Exit.
Use Wrye Bash or Oblivion Mod Manager for installation of mods instead of manual installation.
Use LOOT to fix this issue.
Bethesda Game Studios is known for its extensive mod support, and Oblivion is no different. Oblivion mods can be found at Oblivion Nexus or Planet Elder Scrolls.