Hey been running my MacPro4,1 with this drive for a least a month now. One problem I have with my drive is when I enter boot manager (hold option at startup) the ssd does not appear in the list of bootable drives. I partitioned it with lion in one and snow leopard in other. Can't see either. I have another drive installed with bootcamp on it, and previously had snow leopard on that too. Computer sees that drive no problem. But when it comes to the ssd, boot manager can't find it 90% of the time. Note that if I dont enter boot manager at startup, the computer boots from the default OS on the ssd fine. So the drive works fine. Things I have tried to fix it: - disconnect all external USB and FireWire devices - turn off all Bluetooth devices - Reset MSC. - disconnect power cable and hold power button for 10s. - reformat drive and reinstall OS lion - reformat drive and reinstall snow leopard - ran apples hardware test and 3rd party (no apparrent problems with drive or computer) Nothing has worked. In the process of updating the drives firmware to the latest one. Any suggestions??