According to Speccy, this mobo has four RAM slots. According to BioStar (http://www.biostar-usa.com/app/en-us/mb/introduction.php?S_ID=558#specification), and my own visual inspection, it has two RAM slots. I've reported this before, after I relied on Speccy to justify the purchase additional RAM. Fortunately, I have another mobo that may be able to use the memory.
it gets a few things wrong now and then; wrong temps, type of drives, graphic card memory and in your case, available slots.
all I can say is it doesn't hurt to get a second opinion from another program source and do a visual inspection where ever possible.
the Admins and Devs do know about these issues but no word on any sort of solution as been made to my knowledge.