What info are you getting in BIOS regarding the timings.
CPU_Z may be wrong in reading the values.
Double the values and you will get what might be set in BIOS
It would be 8-10-10-30.
If you put them at 1333 Mhz how are they reported in CPU-Z ?!The way the memory is read by the software reminds me of Memtest 4.20
Note : I am a FX 4100 owner and i can tell you will gain nothing from using 1600Mhz over 1333Mhz ,what to say about using 1866Mhz.
I ve tested the CPU a lot and only increasing it s clock speed and setting the Hypertransport to 2600 MT (opposed to 2400 auto) gives performance increases.
Maybe a new BIOS is needed to be able to set the RAM at 1866Mhz.
What happens if you install only one stick ?Does it go to 1866 Mhz?!