This problem is with an '06 MBP CD (not C2D) 2.16. When it's running on battery only, with the charge indicating 99-100%, it will suddenly just shut off without warning. There's no problem when connected to AC. I've conditioned the battery pretty often and coconutbattery seems to imply all is well, showing 108 loadcycles. If a replacement battery solves the problem, it might be worth it, but with an older machine I'd hate to spend the money and find out it's something else. Any ideas? Plus it's running pretty hot. smcFanControl shows as high as 72c -about 176f! Although it does get down to 38-40c at times.