are you running 64 bit on snow leopard ??

Snow leopard defaults to 32 bit kernel when you boot up. I don’t know why apple hasn’t given us a choice to permanently boot up in either 32 bit or 64 bit.  If you want your snow leopard to boot up on 64 bit kernel, you need to hold the 4 and 6 key when your mac boots.

You can verify the kernel mode by checking the  :

About Mac – > More Info – > Software

Here is what mine looks like after I booted in 64 bit: