Have laptop Samsung r538 dt02ua. Core i 3 380 M. Support for 4 GB of RAM one strap, were 4 and 2 both at 1066 mhz, pulled both put 4 GB 1600 mhz goes to reboot. Memory working, on other laptops working. Like well need at a reduced frequency to work? Or controller in this laptop "does not know how to fall" only on 1066 ? In the BIOS like timings to change. That is possible in such cases generally do? well, except replace with another bar.