My Macbook Pro keeps shutting down before I reach zero percent battery and often when the battery still has 25% left. I am wondering if this is a software issue that may be fixed or if there is something incompatible with my hardware. I am running 10.6.4 with a 2.16 GHz Intel Core Duo, 2 GB 667 MHz DDR2 SDRAM memory bought in April of 2007. My mac was originally running Tiger, but a few months ago I updated to Snow Leopard. Could this be causing my problem? Please help, it will be very much appreciated!