The Eidos Forums have details on a second patch that's now available for THIEF, updating the stealth/action reboot to version 1.2 the next time Steam is restarted. This addresses several issues, and while they expect this to be beneficial to all, they also offer instructions on how to revert to the earlier version, which in a twist, is now considered a beta. Those forums also now have a stickied post on essential tweaks and fixes for the PC edition of the game. Here are the version 1.2 patch notes:

• Fixed an issue where, for some users, controller right stick would not turn the camera and controller hints would not appear.
• Fixed an issue where, for some users, the keyboard mapping menu would immediately map a key and then hang.
• Fixed an issue with the fog when SSAA was enabled that was introduced in v1.1.
• Fixed a crash when the user had 99 saves and tried to access the save menu in game.
• Added an option to the launcher configuration dialog to run the 32-bit version on a 64-bit machine. The 32-bit version has several features disabled causing it to use less memory, providing a smoother experience for users with lower spec machines. The checkbox for this option can be found in the display tab of the launcher options dialogue.
• Update: Deploy additional DLLs with the game to avoid issues with corrupt DLLs on user machines, which could cause the game to not start at all.
• Update: Moved Lockpick and Frame Search helper to the HUD menu and will now also affect mouse/keyboard.
• WARNING: Disabling Frame Search helper while playing with mouse/keyboard could make it very hard, if not impossible, to find the button.
• Various performance improvements.
• Various crash fixes.