+1!
adaputter: do a disk clean up everyday
Probably, that won't help much with RAM memory problems - I deem it too much (and my Win7 does automatic defragmenting on a regular basis)
RAM usage is heavily connected with the OS used. I play on an i3 CPU with 6 GB - quite o.k. Newer systems may require more - you might want to check comparable PCs to see where you stand.
A well-known Flash flaw is directly connected to the game: Rising blockage of RAM over time. Thus, the game may react differently between the first and the tenth game. Therefore, it's paramount to restart the browser from scratch every now and then, for example, once a day or before each game.
Have fun!