I had many problems with Facebook while using Internet Explorer. I switched over to Firefox and it eliminated most of them.
Many of the Zynga games, when they are first introduced, are extreme memory hogs. It takes them several months to get it cleaned up and then everytime they do a major update to them, the hog comes back to the trough.
I just keep clearing my PC's cache and temp files on a daily basis and that seems to keep the worst of it down to a minimum.