I continue to see manifestations of a redisplay bug with mouseover
highlighting in Gnus Summary buffers.  It happens fairly seldom and I
cannot reproduce it.  It happened again today on GNU Emacs 23.0.50.3
(i686-pc-linux-gnu, GTK+ Version 2.12.0) of 2007-11-06 on escher, and I
made a screen shot, attached below.  As the image illustrates, only one
character width is involved, and this is always how it shows up now and
for many months (whereas earlier manifestations usually involved several
character widths, usually with non-highlighted gaps).  The image
suggests that the position of the remnant mouseover highlighting was
occupied by the cursor, but I am sure of this.

Steve Berman