I have been reading several threads on freezing problems with 2007 Imacs and Snow Leopard. I have tried many suggestions, but none have resolved the problem. My constant freezing can be directly attributed to the amount of network downloading I am doing. If I am downloading one file or Dropbox is syncing a file - everything is fine, but if I add another download at the same time, I guest instant freeze with the spinning wheel of death. It doesn't matter whether I am using wired or wireless. On Tiger it works fine. I can't seem to figure out why multiple downloads cause the freeze. Anyone have an suggestions?