This evening, I upgraded my Debian/Sid system via apt-get, and several packages were installed. Among them were several kde/qt packages as listed below to -19.deb version and the icons were not visible on the desktop (broken as before).
-rw-r--r-- 1 root root 894 Jan 7 20:26 qt-designer.list -rw-r--r-- 1 root root 293 Jan 7 20:26 uic.list -rw-r--r-- 1 root root 308 Jan 7 20:26 libqt2.list -rw-r--r-- 1 root root 261 Jan 7 20:26 libqutil1.list -rw-r--r-- 1 root root 261 Jan 7 20:26 libqt2-mt.list -rw-r--r-- 1 root root 261 Jan 7 20:26 libqt2-gl.list -rw-r--r-- 1 root root 239 Jan 7 20:26 libqt-mt-dev.list -rw-r--r-- 1 root root 239 Jan 7 20:26 libqt-gl-dev.list -rw-r--r-- 1 root root 8868 Jan 7 20:26 libqt-dev.list I then downgraded these same nine packages from -18.deb files I had saved from the previous version, and everything is now working as it should (icons appear again). ii libqt-dev 2.3.1-18 Qt GUI development headers, static libraries ii libqt-gl-dev 2.3.1-18 Qt GUI development libraries for GL version ii libqt-mt-dev 2.3.1-18 Qt GUI development headers, static libraries ii libqt2 2.3.1-18 Qt GUI Library (runtime version). ii libqt2-gl 2.3.1-18 Qt GUI Library (GL version). ii libqt2-mt 2.3.1-18 Qt GUI Library (runtime threaded version). ii libqutil1 2.3.1-18 Qt Util Library ii qt-designer 2.3.1-18 Qt GUI Designer ii uic 2.3.1-18 Qt ui compiler
