I went back and tried Tc version 3.8.4, Xorg-7.4 and Firefox 6.0.2....and did not see the problems I saw using Tc version 4.0. For me at least...it seems Tc version 4.0 and Xorg-7.4 have an issue.. For what it's worth, a custom financial program I run, also had display problems with Tc version 4.0 and Xorg-7.4 that did not occur when using Xorg-7.5.