Unity: some of my windows are occasionally going all white and refresh takes many mousovers

[Peter Teuben]

One of the recent (last month or so) updates is regressing my windowing
experience terribly.

A few times per day a window plus borders goes totally white, you mouse
over the next window,
and it seems to inherit that blank, you mouse back, and sometimes it
picks this back up to normal
again.  But sometimes other windows get this infection as well, and it
can take me many mouseovers
to get back to work. This lovely experience can easily take 5 to 10
seconds. Not a good thing to happen
when you have to show off some work.

Anybody seen this before?  

FWIW, this is on a Thinkpad T61p, which has given me issues before (in
older Ubuntu) w.r.t windowing
and menus, something I've never seen on other linux'.  I should add I
have a near identical Ubuntu 12.04LTS
on a a desktop that doesn't show this behavior. So perhaps it's special
to the Thinkpad X driver.

peter