2 problems: double login, plasma error on exit

[pwabrahams]

I'm having two problems that may be related:

1. When I log in, Kubuntu whirs for a minute, then returns me to the login screen again. When I log in a second time, I'm OK.

2. On exit, I get the message "Plasma desktop shell closed unexpectedly". I still can shut down without further errors.

These aren 't fatal problems, but they're annoying.