since several months I observe a strange problem mostly in iceweasel
(from current Debian testing), but also occasionally in other
applications: quite often one or a few characters on a web page lack
some parts of them (for example, there is a horizontal
background-colored line in the lower part of an "h"). The error affects
only some characters of some fonts of a certain size. All identical
characters of same font and size are always affected equally. A cropped
screen shot which illustrates the problem is attached to this message.
Restarting iceweasel makes the problem disappear in it's previous
incarnation: all letters will be shown properly, or some other might
There is another display problem in iceweasel which may or may not be
Sometimes, when the contents of a web page are redrawn after switching
virtual screens or scrolling, some part of the text is replaced by
nothing or cruft (random-looking bits). One method to make this stuff
disappear is force redrawing by switching virtual screens or selecting
the affected text.
This problem has persisted since at least three months. Despite spending
quite some time I could not find any solution or reference to something
Has anyone ever experienced something similar?
This problem could be hardware-related, as another machine also running
Debian testing is not affected by it.
The display controller on the affected machine is identified by lspci as