Sounds like you're playing it too long Crab Lungs put me onto a fantastic program called games booster.
http://www.iobit.com/gamebooster.html
Download it, open it up along with task manager and keep an eye on football manager on the PROCESSES screen, not the programs screen. It will crash dump at around 1million K of memory apparently, but I just run games booster every time it gets up to around 500,000 k and then there's no problem.