Created attachment 110907 [details] demonstration See my gif recorded on Arch Linux, partition manager 3.3.1.
I won't fix this for partition manager. First of all we are moving away from running as root to running without root and using KAuth. Then polkit dialogs are used and they don't have this problem. If you want please reassign this bug to kdesu.
It is part of KWidgetsAddons. But it cannot be fixed there either, because the application dynamically adds the error text. Also, the actual layout is computed by the Qt layout classes.
BUt are the any significant users of kdesu left? Like I said KDE Partition Manager should move away from kdesu, I think in next+1 feature release.
ok, thank you all.