I got Gigabyte GA-EX58-UD3R MB and 2x2gb Supertalent 1333 ram and I have this problem.
If I manually don't set the freq to 1333 in bios I get only 2 GB ram and working on 1066. When I set the freq to 1333 I get all 4 of ram until power off. If I turn off the PC and then power it back on I get 1333hz ram but only 2 and in Win 7 x64 saying 4gb but 2 usable. What might be the problem?
I updated to latest bios and still the problem. I read on the net cases of bent processor socket pin but its weird that every time I change ANYTHING in the bios again it shows 4 GB @ 1333 until power off.