For what it's worth, the color highlight (the one that shows which program has focus) is also drawn as a plain rectangle with no shading.
On closer inspection, i noticed that murrine exhibits minor glitches, too. I suspect now that this is due to a general problem with libcairo2, so this bug report may be misassigned. Anyway, I can't say for sure what's going on. Feel free to close this report or reassign it if you are positive that Docky is not to blame for these glitches. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org