unresponsive screen graphics

[Ralf Mardorf]

Could it be an autostarted or dbus started daemonized dolphin or
something similar KDE related that grabs the desktop, or at least
grabs some desktop features, competing with the default DE? Ubuntu
packages autostart everything that could be autostarted, so apart from
usual issues, that could happen after installing competing apps, Ubuntus
very bad package policy, easily could cause additional issues.