Well, your graphics card seems to be the weakest link, and 32MB is not much for high res images!!
I would say that more graphics memmory would help! Ebuyer have a GForce FX5200 with 256DDR ram for £60 inc vat (click here).
Although the chip set is not the fasted, its more than enough for image work, and 256Ram is alot of mem!
If your really tight, the same card with 128Ram is your for around £50!!