From https://bugzilla.novell.com/show_bug.cgi?id=440395 I'm using fresh KDE4 from http://download.opensuse.org/repositories/KDE%3a/KDE4%3a/Factory%3a/Desktop/openSUSE_11.0/ When you right click on scrollbar of Folder View plasmoid the context menu will be positioned at position that looks random. There is a screenshot in the downstream bug
*** Bug 175686 has been marked as a duplicate of this bug. ***
confirmed to be an upstream issue in Qt; bug has been filed with Qt Software.