I just had another Out of Memory error.
Task Manager said EOS.exe was usinf 1,505,614K of memory.
My computer only has 2GB of memory, DOH!!!
This was with a Map Editor map of 4000x3200, 100% cities and resources.
After making the map and saving it I exited back to the desktop and restarted EOS.
I was running at about turn 60 I believe when I got the error.