X11 -- disappearing text and bitmaps

[Mikhail T.]

Hello!

After upgrading to FreeBSD-8.1 and Xorg-7.5, I started having a strange 
problem with X11. Things start up fine, but after short while both 
firefox and thunderbird begin showing simple straight lines instead of 
rows of text (both in the menus and in text widgets). The pictures on 
web-pages would not repaint either.

The KDE's (KDE-3.5.10) taskbar also loses all icons and text -- and 
becomes simply gray. If I click, where I remember the application's 
button is on the taskbar, I can still restore/minimize the window or 
start a new instance, however.

The xterms don't have this symptoms -- text inside the xterm windows is 
just as visible/usable as it was.

Restarting Xorg is the only "solution" so far... I increased the max 
shared memory to:

    kern.ipc.shmmax=536870912
    kern.ipc.shmall=163840

but the problem didn't go away... Any ideas? Thanks!

    -mi