Emu keeps locking out

Not just PJ64 but MUPEN and I assume every other emulator alive keeps freezing my machine whenever I enter a shop in Zelda 5 (or enter any new area that requires memory reloading) and in Goldeneye happens randomly. This is extremely fucking annoying 'cuz the power button on my new computer only works when... the OS is NOT locked out. The only way to restart my comp from the frozen state is unplugging the cord.

I'm on WinXP SP2, 3 GHz dualcore Pentium D CPU, 1 GB RAM.

PJ64 ran Zelda perfectly on my old computer which also had XP SP2 but half the CPU speed and it wasn't a dual-core like this one. The Mupen and PJ64 configurations are exactly the same as the previous, since I copied the .inis.

This freezing must be 'cuz of the dual-core processor. Any ideas on a solution?

How?

Oh, I tried that already, it made no difference. I thought you were referring to some core optimization configurable in PJ64/Mupen.