Are you using Qt or GTK components? Usually these types of problems are related to the GTK theme used by the KDE desktop so you should try to use another GTK theme in system settings.
Hi!
No, I'm using Qt4 compiled Lazarus 1.0.14/fpc 2.6.2 on OpenSuse 43.2. I don't use GTK widgetset.
No, I changed Lazarus to 1.8, but I have many problems with code.
I need to adopt big amount of my code to the new version, because Lazarus 1.8 don't supports all components that I'm using.
OpenSuse 43.2 (KDE Plasma 5) + Lazarus 1.8 + Qt4 - don't has this (topic) problem.