I started a new character in Fallout 1 today and have gotten to Vault 15. But I have encountered a bug that renders the game almost unplayable. Every few seconds the screen will blink/reload, and turn all black. I have to "paint" the screen back by moving my mouse pointer around the screen. The game-screen itself will return the minute I go to the screen border, moving it up, down, left or right. But the entire UI at the bottom of the screen have to be "painted" back with the mouse pointer. Doing this every 10 to 15 seconds is just more annoying than what I can handle. I got the 1.2 version of the game, the one that came in a box along with Fallout 2 and Fallout Tactics.

Anyone know what might be wrong? Does any of the unoffical patches fix this? And which one should I download - I got lost when I saw there were a pages worth of various unofficial patches.

Edit: I think I solved it. I found a fix that runs in the background while I'm playing. I haven't encountered the problem after that - so far, at least.

I found that this only happened if I had other windows open when I started Fallout. If I minimized everything Fallout would run without this glitch.

Click the CHA (character) button, then click done. The screen will return to normal. I'm playing via Gametap right now and this occurs every so often (though, not every few seconds though).

No, it happened so often that clicking the character-menu every few seconds would be too much. But I found a bugfix that works wonder, haven't had it happened once when I use it.

Download the engine tweaks here:
http://www.nma-fallout.com/forum/viewtopic.php?t=36219
This will convert the Fallout games to Direct3D9, which plays nicer with Windows XP and beyond.
You can even edit the config file to add filters and even fix bugs such as AP ammo not working correctly. Also adds mouse wheel support which is handy.

Additionally, you can go into Control Panel>Display>Settings>Advanced>Troubleshoot and lower the hardware acceleration windows uses. But this is sort of a pain to do because unless you want everything else to run like garbage, you will have to keep turning it up and down every time you start/stop playing.