That goes for the rest of you, too. And if you use Outlook or Outlook Express for email, switch to Mozilla Thunderbird if at all possible. Seriously, people see these firefox fanboys and think how lame, it's just a browser. But I have no spyware and I have been using Firefox. It is the very first thing I install on a brand new PC, and the only thing I use for browsing.
But regarding the CPU usage, I was as shocked as the rest of you when I noticed 40% CPU usage. Checking into it with some sysinternals tools, I have just found that the processes that are using all the CPU are ZoneAlarm Security Suite's processes, and the "Bluetooth Support Server" service. Neither of these are spyware, I'm sure of it. But, as to why they are using up so much CPU... I'll have to figure it out.