I use terminator maximized in my first workspace. I have a Firefox 3 in my second work-space and I switch between both with a keyboard shortcut quite heavily. And very regularly, I have to see the content of my firefox window in my terminator window... I have to force a refresh somehow (changing workspace a second time, or minimize/maximize) to see the real content of my terminal.
Attached is a screenshot: on the left pane, I'm supposed to have mutt (you see it on the top, a few lines...), yet the rest is filled with the content of some web page... (except for the central part where some other windows was temporarily displayed through ALT+Tab and that forced a partial refresh...).
It it is somehow related to GTK, as only some GTK widgets have that effect... for example with xchat, I only get the input field displayed on top of my terminal and with firefox only the part that displays the web page (the tabs and toolbars are never displayed above the terminal).
I use terminator 0.9-1~beta1.7 (Debian package from Nicolas Valcárcel <email address hidden>). libgtk2.0-0 is at version 2.12.10-2. I'm using current Debian Sid.