It would help if you listed what PC you are using, what type (laptop, desktop), what components it has, SATA mode, SATA driver, and what OS you use. Diagnosing things like this is not easy without that information.
Talking to Intel support is not a bad idea too, and the first thing they would ask you is the same thing I did.
Have the same error with SSD 520 120GB on Dell T3600 with PERC H310 Controller. ToolBox 3.1.2 (the latest available). No RAID configured, only one SSD drive connected, latest firmware on PERC and latest (A007) Dell BIOS, fresh install - all by the book.
Quick Diagnostic also comes up with "Error reading the selected SSD... call support)
Spoke to Dell support - got an understandable run around since they are not obligated to support some 3rd party tool (Intel Toolbox optimizer in my case) and troubleshoot the errors it produces.
Thought it might be PERC controller acting funny, removed the PERC controller card, plugged SSD to motherboard directly as a secondary HD (not to screw up existing Win7 install) and booted from another (Win7) HD. Run Toolbox -> Optimizer grayed out (even though SSD drive is shown in Toolbox) with message "S.M.A.R.T has to be enabled..."
That last part is annoying to say the least - MB has Intel C600 SATA controller in AHCI mode, Intel driver and the errors are even more severe then with PERC.
Will be calling Intel support Monday, but would appreciate any input from the community.