FS2004 and video card settings

I have an nvidia FX5600 video card with 256KB of video memory. My computer is a Pentium 4 3.2GHz CPU with 1 GB of RAM. Most of last year I spent using a relatively mature nvidia driver version 56.34 and that worked relatively well. The only complaint I had was that every once in awhile, my video card, I think, overheated and I got twinkling video artifacts sprinkled in the scene. To help with this I ran with one side of the computer case removed and for the most part the problem was tolerable, i,e, it didn't happen that often. A couple of weeks ago, however, I got greedy and decided to upgrade to a newer driver to see if it would be more efficient and maybe help the overheating situation. So, I installed a recent nvidia driver version 91.47. I played around with settings like antialiasing and anistropic filtering on this driver and immediately started getting some strange visual effects I didn't anticipate. Specifically, I lost the aircraft preview in the Create A Flight menu (just a black square now), and the screen that immediately precedes the flight is also black except for the progress bar showing the percentage of things loaded. The sim itself, once it starts, seems okay so I guess I should be thankful for that. After seeing this, I played some more with the video parameters and actually succeeded in getting the aircraft preview and loading progress screens back. However, when I got to the sim itself, the screen was hosed and unusable. It was quite fragmented and pixelated. Interestingly enough, if I pressed the Alt key to get to the menu bar at the top, everything cleared up and went back to being normal. However, it wouldn't stay that way. As soon as I made a menu choice and the top bar returned to being hidden, the whole screen was hosed again.Okay, figuring that this latest driver maybe had problems, I dropped back and installed the earlier nvidia version 81.98. My experience with this one was pretty much the same as with the later driver described above. Does any of this resonate with any of you more knowlegable people and can you offer me any insight into the cause of my difficulty and perhaps some possible solutions.Stan V.