Can the mid-2010 Macbook support more than 4GB of RAM?
It depends on your particular model, but I believe that the answer is YES!  The great people at Other World Computing sell RAM upgrade kits for MacBooks.

To be sure:


Go to Apple -> About This Mac
Click More Information.
Look at the Model Identifier.


If it is MacBook 5,1 or 6,1 or 6,2 you can put 8GB of RAM in it.

http://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/Macbook_selector