Hi. I am getting the same error as you are. I have KDE 3.2 as well but didn't have k3b with a lower version so I'm not sure if that is what causes the issue. I know I was having some trouble with xcdroast recognizing my second drive as a writer, maybe this has been dragged over to k3b too. One of my cd-rw's works (the slower one) but the other doesn't.
I will try and do a search on what that error means exactly. I'll let you know when I get a solution.