CPU Usage by WW

Yesterday my PC was doing some very strange things. Just seeming to hang up. I thought I’d have a look at the processes and see if there was a clue there.
Well, lo and behold, WW has the CPU pinned.
From watching Task Managner for a while in the foreground while working around it, I noticed that WW does easily relenquish resources to whatever needs them.
Except for the distributed.net client that I run which uses spare CPU cycles to solve mathematical challenges.

My question is:
What is WW doing that it needs that much CPU?

When it’s sitting in the tray, it shouldn’t be using any resources at all in my mind. I think that it should require resources only when it actually reaches out to do an update.

Does it continue to act this way after you reboot?

What version of WW are you running and what OS?