Ok, So i added an aftermarket OCZ SSD to my late 2008 MBP 15" 2.53Ghz. I would close the lid and it would go into hybernation. Then on opening the lid it would freeze coming out of hybernation. When the machine goes into hybernation an image of the ram is stored on the SSD. This is then loaded back into ram when the machines wakes up. It is at this point, when the image is being loaded back into the ram that something happenes causing the machine to freeze. It may be an SSD power issue but I am unsure as to the exact cause. I did some research and discovered that when the machine goes into 'hybernation' and to 'sleep' are two different things. When the machine goes to sleep it does not put an image of the ram onto the SSD. I thought this might solve the issue I am having. I cant find a way in OS X to controle this but I did find this app: http://www.jinx.de/SmartSleep.html It allows you to set the machine to go to 'sleep' or go into 'hybernation'. I have set it to sleep and have not had any issues so far. I will keep you posted.