I'm posting this hoping someone has an answer for my dilemma. This weekend I installed a Samsung 256 SSD in my MB Pro unibody 15. I formatted the SSD with GUID and did a zero erase. I then installed OS X from the disc that came with my laptop three months ago. This had 10.5.5 on it. Once the install was completed and the computer re-booted I came to the migration screen. I selected the option to migrate my data from the old hard drive that I connected via a SATA docking device. This then transferred my user folder, applications, preferences etc to the new drive. I then ran Software Update and installed all the updates that were relevant. I'm now experiencing frequent system hangs where I get the spinning beach ball. At first I thought it was related to Safari as it happens there a lot. But then this morning it's happened numerous times in the finder. My feeling is the problem is related to the data migration. However, I dread the thought of wiping everything and re-installing as that took me quite some time to complete on Sunday. Any suggestions on how I might remedy this problem?