From my reading, using 8gb (or even 16gb) is not an issue, but using the faster 1333Mhz RAM '''is''' apparently a problem.
The article quoted below shows in detail (with video) how to hack the RAM to run at a lower speed. It uses the free Windows only ThaiPhoon burner, which can only be run from BootCamp or a BartPE disc (not a VM!).
''The 4GB my mid-2010 13″ MacBook Pro came with just wasn’t cutting it for me anymore so I picked up a couple of 4GB DDR3 1333MHz sticks for about $40. If you’re like me, you don’t tend to pay too much attention to the nitty-gritty details of something as trivial as a RAM upgrade. Of course, I knew that my model MacBook Pro only supports up to 1066MHz DDR3 RAM, but I assumed that the faster RAM would downclock itself to match the 1066MHz limitations of the MacBook Pro itself. Unfortunately, this was not the case and when booting with 8GB of RAM, my Mac’s loading indicator would freeze when booting the OS.''
''After that, simply power down your virtual machine, eject your bootable Windows disc and flash drive, and install both 4GB sticks of RAM into your MacBook. The stick you just reflashed to 1066MHz will cause the remaining faster 1333MHz stick to downclock to 1066MHz as well and your Mac will boot right up without freezing!''
From my reading, using 8gb (or even 16gb) is not an issue, but using the faster 1333Mhz RAM '''is''' apparently a problem.
The article quoted below shows in detail (with video) how to hack the RAM to run at a lower speed. It uses the free Windows only ThaiPhoon burner, which can only be run from BootCamp or a BartPE disc (not a VM!).
''The 4GB my mid-2010 13″ MacBook Pro came with just wasn’t cutting it for me anymore so I picked up a couple of 4GB DDR3 1333MHz sticks for about $40. If you’re like me, you don’t tend to pay too much attention to the nitty-gritty details of something as trivial as a RAM upgrade. Of course, I knew that my model MacBook Pro only supports up to 1066MHz DDR3 RAM, but I assumed that the faster RAM would downclock itself to match the 1066MHz limitations of the MacBook Pro itself. Unfortunately, this was not the case and when booting with 8GB of RAM, my Mac’s loading indicator would freeze when booting the OS.''
http://tylermilner.com/?p=342