My game is randomly minimizing every now and again. I've tried it with and without any other program open, and it happens both ways, which rules out a background program running.

Often I'll see a mouse pointer in the top-left corner, and then after I click a handful of times, it'll minimize. I should also mention it wasn't there for most of my first playthrough, just a recent kind of thing...

Any thoughts or fixes or something I may be missing?

The symptoms my game was exhibiting:

• Crash right at Bethesda logo before main menu appears
  
• During gameplay, would minimize to desktop at regular intervals
  
• Distorted audio during minimizations

Managed to find a workaround!
It's an application of a fix for the same problem within Fallout 3.
This may or may not work for you, though.

IF you have FFDshow installed:

• Open the configuration exe's for both the audio and video decoders
  
• Click DirectShow control on the left, and make sure "Don't use ffdshow in:" is checked
  
• Now, click edit and add FalloutNV.exe to the exclusion list for both audio and video decoder

I've been able to load the game successfully with an unaltered .ini file and made it through character creation/exposition without a single minimization.
Much appreciation to those with the same problem who can further test this; or to those who can reproduce the minimizing with FFDshow.

I dont get the "fallout ended due to an unexpected error" message / crash

I get the screen pauses then goes black then all white and you cant get out of the white screen
I have figured out that you can still move around but all you see is a white screen. so I remembered that start > 2 clicks down means save game > then start again and > click all the way down to exit game and then I have to re start
Soo after all these crashes Im getting good at playing the game blind!