The MBPs with NVidia chipsets (including the 13" mid-2010s, and mid-2009 models sold in 2010) are very finicky with RAM speeds. You will generally need to run 1067MHz DDR3 speeds, rather than faster speeds (some people have reported success using faster speeds, but as you've found, there's no guarantee it'll work).
Later MBPs with Intel chipsets are not picky and will happily run faster speeds...