Got mushkin 2x4GB for RM246 yesterday. Unfortunately the shop give me 1333Mhz. It's actually a simple mistake. Told them I need ram for mbp 2010 and straight away the seller said need to use 1066Mhz. So I said OK. Unfortunately he take 1333Mhz. I also don't realize.

After install, my mbp will not boot. Mixed 1 old 2gb and 1 new 4gb it boot fine. Dunno why the mbp 2010 really can't run on 1333Mhz. When I mixed it will auto underclock the 1333Mhz so it's will run fine.

After searching around, I use thaipoon burner (windows - need to install windows for this.) software to change the memory data from 1333 to 1066. Just need to change 1 stick. Fortunately the mushkin memory allow write access to memory data.

Now running 8GB.