I can confirm this bug. I have a laptop with Debian unstable and KDE 4.3 and a desktop PC with Debian testing and KDE 4.2 and both are affected by this bug. However on my desktop PC (KDE 4.2) this problem just occurred recently, so I don't think it's caused by kdelibs5.
I think the real cause is a package that has recently migrated to testing (and of course is also in unstable). Sadly I have no idea what it could be.
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