I've an OCZ Agility 3 SSD 80gb, I got it and installed everything fine, was working good for a few days, then the first of this problem happened: I get a bluescreen, randomly (first time was in a browser that isn't installed on it and second was in a game that also wasn't installed on it, both on the HDD) - I reboot, and It automatically boots to my HDD, the system doesn't recognize my SSD anymore, and in the booting screens it tells me "no hard disk detected" when normally it displays my SSD there.
After I take the computer apart, and change the sata port, I boot up and it's recognized again. It's happened 3 times so far, the first time I went to the slot above it, the second time I went back to the original one, and the third time back again, so it doesn't seem to be related to that.
I am using an ASUS P8P67 Motherboard, normal version
When you have a bsod some times it takes the SSD out of the first boot device in the boot sequence so if it happens again go to the boot sequence and make sure it is listed first. Also like Dereck47 says try updating the firmware and drivers if they have them.