I see similar symptoms running under VirtualBox 4.3.12r93733, on two different laptops.
1. Minimizing firefox freezes the screen.
2. Exiting from gnome-terminal sometimes leaves the window mapped. Starting another terminal makes the first window go away.
One of the laptops says this:
$ uname -a
Linux cesar-u64-dev 3.13.0-35-generic #62-Ubuntu SMP Fri Aug 15 01:58:42 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
$
Both are updated to latest software about once a day. In particular, both have the 3.13.0-35 kernel, and have had all the recent ones.
The problem so far is just an annoyance, if I have a way to log in and blow away firefox or gnome-terminal.
I see similar symptoms running under VirtualBox 4.3.12r93733, on two different laptops.
1. Minimizing firefox freezes the screen.
2. Exiting from gnome-terminal sometimes leaves the window mapped. Starting another terminal makes the first window go away.
One of the laptops says this:
$ uname -a
Linux cesar-u64-dev 3.13.0-35-generic #62-Ubuntu SMP Fri Aug 15 01:58:42 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
$
Both are updated to latest software about once a day. In particular, both have the 3.13.0-35 kernel, and have had all the recent ones.
The problem so far is just an annoyance, if I have a way to log in and blow away firefox or gnome-terminal.