Comment 4 for bug 66534

Well, it's certainly a duplicate of #62439.

Actually the very same problem appears with every backend, so it's a problem with kde.

IMHO, the best solution is provided in ARK Linux, however it's also partial as ARK's ark (funny name for a distro, btw :-) ) doesn't open .zip properly either.
I use a port of their unzip which works correctly with russian names.
When ARK Linux team makes a fixed version of ark, I will port it to Kubuntu. Until then, just wait?