I'll try the uninstall and reinstall. I don't know how valuable my report will be, though, because I copied many, many dependencies over from another VL partition and they won't be removed if I uninstall K3B. I'll give it a go, though.
After all my copying of libs I did get K3B to run. I burned copies of four DVDs and they were all good. So I didn't have to boot into Windows for copying--I'm happy about that!