I have only used the ignore function once before. I tried to find it tonight and couldn’t find it. Does it still exist, of am I several software revisions behind the curve?
No, it’s still there. You can find it by clicking on “User CP” (look in the blue bar underneath the thread titles) and then clicking “Edit Ignore List.”
Now then, who said that? 
Unfortunately, there is no easier ignore button. I’ve requested it on weirdaaron’s Greasemonkey script, but he hasn’t got around to it yet.