game crash during turn waiting or saves

[Carnex]

So its gotten to the point where i cant actually play the game anymore i cant make it through 2 turns (crashes in the turn waiting part) and i cant save more than once (crashes when i hit save) if that.

Turn 235, 40 cities and around 60 units
Playing on huge earth map, quick game with everything set to min.

specs
Windows vista (32 bit)
4 GB RAM
AMD Phenom II X6 1090 3.20 GHz processor
ATI Radeon HD 5770 PCI-E video card

Cheers,
Ash.