I can get into the BIOS with both plugged in but the Samsung won't show up. If I ask it to auto detect I can find the drive as the auto detector will freeze for a little bit when it doesn't on the other slots, but the hard drive info wont show, like the size of it, model number etc.
Thats never a good sign, Try it on another computer or a friends computer see if you can read the data off of it. If you dont have another computer or a friend who could help you could purchase a SATA to USB adater cable, but given how the hard drive is causing the BIOS to freeze it may just be a waste of money.
Did you make any other changes to the computer, unplugging or plugging stuff in?