Download the free version of Parted Magic that includes a built in secure erase utility and a friendly GUI
Follow the secure erase tutorial here;
http://www.overclock...th-parted-magic (sorry for the redirect guys - but this is simply the best tutorial out there for the this operation IMHO)
This will completely erase all the blocks on the SSD - everything except those reserved for over-provisioning. This is accomplished through an actual flash of the memory blocks. It wipes everything.
Your SSD will be back in factory OEM state at this point. Try the installation again using best practices i.e. no other hard drives attached etc.