game keeps locking up

i have a more than adequate system to run SEV but i keep
having to deal with it locking up. From 10-50 turns into
a game it just stops in the middle of the end of turn
sequence. I have tried defraging and only save one game
at a time to keep the memory clear but it appears to leak
into my system and the CPU shows 100% usage and nothing
will work. Sometimes i cant even get into windows task
manager its locked up so bad. I have tried smaller games
with less units but i want to play the game as it was
made, a wide galaxy with alot of action. VERY frustrating
to have to reboot my computer, defrag, and go back to an
earlier save over and over. Any fix on this? Wonderful
graphics and concept but runs nowhere near as clean as
SEIV ran.
Tim (plasticpanzers)