My MBP Specs: 1.83GHz 1.5GB Ram 160GB OS 10.5 Replaced Fans Whenever I am trying to convert a movie file using VisualHub, rip a movie via Handbrake, or burn a DVD using Toast Titanium 8.1, MacBook Pro completely shuts down. I'm certain its an overheating issue, but what can I do? I replaced the old fans and have heard some talk about thermal paste. Has anybody had success with this? I'm also downloading smcFanControl as we speak. Any insights would be great. Let me know what you did for yours! Thank you in advance.