Psp not working properly,cuts off when the games loading on two different games on footbal manager?

im playing football manager 2011 at the moment and in two of my games i get through around one season and as it loads to the next season it just cuts off right at the end of the load box. my psp is quite old but dont know if its the psp or the game or the memory stick. its fine with any other games like fifa and things but just cuts off and its annoying because if i dont save it i have to go back to where my last save point is after reloading the whole game again. can somebody help me how to fix this please?