Installed new RPi 2B today, using HDMI-DVI to 1920x1080 monitor, running Raspbian. Everything worked as specified, including the full monitor resolution, until after I added a second username. When I log in as the second user and key "startx," the screen blanks, "Wastebasket" appears in the upper left and the -- I guess you call it the "Start Bar" as in Windows, except here it's at the top -- Start Bar tries to appear but immediately disappears. It flickers in and out, causing the Wastebasket to jump up and down with each iteration, frequency about twice per second. The only way out of this condition is to power off.
I tried Googling for the answer but lots of messages concern startx. Has anyone else seen this problem?
Thanks for your attention.