my mbpro decided to run out of batt halfway through the recent OS update.

unfortunately im having problems with it now,
- start up takes around 10 mins
- system refuses to shut down (notifies me that i would have to hold down the power button instead)
- my finger slide gestures do not work

have tried reinstalling the Snow Leopard but i cant go through with the restarting stage, also ran Disk Utility and Repair Disk yet there's still no difference.

can anyone help me with this? thanks.