Command tool disappears

I've had this problem for awhile but I think it
happened when I upgraded to fedora 21. (which installs ddd
3.3.12)

I like to have the command tool window up but sometimes it just
goes away? I can get it back with Alt-8 or the menu item but it
sucks that it goes away! It seems to happen whenever I switch
work spaces but I'm not sure. I run mate so I don't know if it
happens in Gnome.

Any ideas ???

Thanks.