i've problem like that but in a VAIO Ultrabook with Hybrid
I chat 4 o 5 hs with the tech service but they didnt help.
I disable the RST(the bios doesnt have UEFI to disable)
when it boots and I should choose the partition an error occurs and said i should install drivers
this occurs for W7, Kubuntu, Ubuntu and debian OS
if anyone can help me i would be very thankful
p/s: sorry by my english