ok I am finally able to recreate this error. someone mentioned here or in another post about it being a memory allocation problem because of all the frequent pausing going on during a game.
To test this theory, I played 4 games. The first 3 games were played 20-40 years. I tested out The Duchy of Barcelona, The Kingdom of Jerusalem, and The Duchy of Silesia. While playing, I never exceeded the speed "Above Normal", and instead of pausing, I used + and - to gradually lower the speed to "Very Slow" before finally pressing "Pause". During these games, there was never any lag, and everything went smoothly.
On my fourth game, I played as the Duchy of Provence. After a brief war with Germany after defecting to France after the Imperial crown being passed on to a child, I kept the Speed at "Above Normal", but started using "Pause" without gradually lowing the speed down to "Very Slow" first.
The result was a big fat Fatal Error. This bug is definitely a Memory Allocation issue.
So, to recap, If you never exceed the speed "Above Normal" and gradually lower the speed down to "Slow" or "Very Slow" before pausing, You will not get a fatal error (probably).
Here are my specs in case they are needed for testing in a similar pc, or if anyone is simply wondering:
via ms-7104
intel P4 2.6
1gb ram (2x512) pc3200
pny 7600gs AGP
430w psu
Edit: My next test will be to try to keep everything stable, using the gradual speed-decrease pattern before hitting pause, while using the speeds "Fast" and "Very Fast" instead of "Above Normal".