The page on the motherboard says only ddr2 800 standard. I haven't seen too many boards like that, but from first glance it does look incompatible with ddr2 533.
Its possible you could change the setting in the BIOS, but to enter the BIOS you.d need the ddr2 800.
What you should always do before ordering the mobo or ram is check the manufacturer's web site for memory compatibility.
I just googled Biostar G31D-M7 and bam, there it was:http://www.biostar.com.tw/app/en/mb/content.php?S_ID=386