I think that the problem is related with metacity compositing. I had the same problem but solved by disabling metacity compositing and then replacing it with xcompmgr.
xcompmgr is a lightweight compositing manager.
Now I'm running Maximus 0.4.14, Gnome 2.30.2, Debian Sid on my netbook and xcompmgr and maximus works fine.
I think that the problem is related with metacity compositing. I had the same problem but solved by disabling metacity compositing and then replacing it with xcompmgr.
xcompmgr is a lightweight compositing manager.
Now I'm running Maximus 0.4.14, Gnome 2.30.2, Debian Sid on my netbook and xcompmgr and maximus works fine.