If this error/warning appears, means the terminal is dumb. It can be verified by executing following command at terminal:
$ echo $TERM
dumb
update the following packages from 1:0.26.0-ubuntu1 to 1:0.26.0-ubuntu2, and restart application:
-
libvte
-
python-vte
I found this solution at http://guake.org/ticket/249 and it solves my problem related to Guake.
In ubuntu make sure you have selected Important security and Recommended updates at
System > Administration > Synaptic Package Manager > Settings > Repositories > Updates
Otherwise latest packages will not be available for installing and update.