Gear:
Intel Quad Core Q6600 @ 3500MHz
4GB RAM, 1TB HD, 750W PS
nVidia GeForce 8800 GTX 768MB

Basically what happens is I'll run the game, and from anywhere between 0-10 minutes in (this happens even when I'm changing options BEFORE the game has started!) The game will randomly decide not to take in any more commands from my mouse or keyboard. The game will continue running without a hitch - NPCs will keep walking around, the game world will continue to turn, people will keep talking if I was in dialogue with them, etc. etc. - yet nothing I do to my keyboard or mouse will be picked up by the game. I can CTRL-ALT-DEL out into task manager and manually kill the task, yet the game won't recognize any commands. Outside the game the other applications work perfectly. I can run the game in a window and have access to the start menu and everything, just not within the game window itself. and thats before even loading a save file. just sitting at the game options screen (where you can select a saved game to load) after about 2 minutes it stops responding to the mouse and keyboard.

Additionally, I can miraculously bring up the LIVE menu and that will work fine. So I don't understand - how can my game keep playing perfectly fine with the exception of this control error?

So I've done a little more research on this as far as my own experimentation goes:

First, changing the settings does almost nothing. Highest settings or lowest settings, this problem still persists. I was thinking it may have been a configuration setting in the Fallout.ini or FalloutPref.ini files, but I've tried setting it all back to the original settings. It still did the same thing.

Second, changing the pagefile on my computer allows me to play for another three minutes or so before this error occurs. At a pagefile of 0MB, the error will occur within a minute of playing. From 200mb and up the error will occur after about 2-3 minutes, but it still persists regardless.

Third, uninstalling or tinkering with the LIVE portion of the game will also do nothing.

Fourth, this error has nothing to do with in-game performance. This error will occur even in the initial main-menu with zero activity on my part. So... I don't know, it seems to be a problem with the game itself, not the graphics or whatever.

I have disabled all codecs, but the problem still persists.

I have the latest BIOS, Hardware Drivers (Keyboard, Mouse, Video).

I have also tried uninstalling and reinstalling Microsoft Visual C++ Redistributable and Microsoft .NET runtimes to no avail.

I have optimized this system configuration for gaming, so all I've set all setting to maximum performance. Nothing is set to go to sleep including the screen-saver. I've even removed all non-essential services using the Black Viper recommendations for a gaming system. I've even unplugged any unused usb devices. This system is running at maximum performance, which is overkill to run just this one application.

The keyboard is wired. Its a Logitech G11 gaming keyboard and the mouse is wireless Logitech MX Revolution. The keyboard profile even recognizes that I have Fallout 3 on the computer.

My next step will be to swap the mouse for a wired version and remove and reinstall the game.

And does anyone have any idea of how to fix this?