And this is with the latest beta build right? 1.01 (I think it is) - but called V3 for the software download?
Because I have an old Windows 7 system, 4GB RAM, nothing special - and with the latest build, did not hit that memory issue.
And to make sure you're using clean slate games (as in you started all over from the very start of the game)? Not restoring from the previous build save games?