ghost borders appear in top-left of 8bit display with Human theme

Binary package hint: gtk2-engines-ubuntulooks

Hi,

Ghost frames appear in the upper left of the 8bit desktop when opening menus or windows.

Although the machine has a 32bit display, I've been testing the 8bit mode. From within a vt console, I use
startx -- :1 -depth 8
The machine is
http://wiki.ubuntu.com/LaptopTestingTeam/FujitsuLifebookC1110

The attached pictures show several rendering errors. These errors appear when using the
  "Human",
  "Silicon" or
  "Outdoors" themes.
They go away when using other themes like
  "Mist",
  "Clearlooks",
  "Ocean Dream" or
  "LegacyHuman".
In particular, all screenshots were taken using my preferences, a
mixture of two themes:
window content: Human
window frame: Mist
icons: Human

The mere act of selecting one or the other icon set or window content theme makes rectangles appear intermittently in the top left corner!

o The bottommost blue line remains after selecting the top panel's application menu. It persists (or is redrawn?) across refreshes (even switching back and forth between vt2 (text console used to startx), vt7 (normal 32 bit session) and vt8 (8bit).

o Similarly, there's a blue vertical line in the top panel left over
after displaying the two other gnome menus ("Orte" and "System").

o Moving the window of the snapshot tool draws blue corners within its frame, see depth8-snapshot.png file attachment.

o Please notice how the menus have no frame. In fact, every time the blue border artifact appears, the corresponding menu has no frame!

o The picture depth8-blue-border.png reveals that the dimension of the blue rectangle that's drawn in the top left is a phantom exactly the size of the popup-menu that appears in the center of the screen.

Likewise, I see a blue rectangle appear just before the middle menu ("Orte") from the top panel is rendered, exactly the size of this menu.

o The Xserver crashed once while testing all of this. Sorry, I forgot the details. It'll hopefully go away when fixed.

Color issues:

o There's always a rectangular zone around the mouse pointer where the background picture colors are slightly changed (alas, the mouse is not visible in the attached snapshots).

o Similarly, the desktop icons for FTP, SMB, CD-ROM etc. reveal
rectangular areas around them where the background color is changed --
I thought the icon's background is transparent and would never appear.

o The picture depth8-menu shows the surprising two-color highlighting of the top panel's menu while the menu is selected. It looks weird and reduces readability.

o Also, this picture shows color artifacts for the title font of
active windows. Why is the background of "Bildschirmfoto speichern" greenish while the rest of the title is brown?

It's the same green as the square around the mouse pointer.

I'm using Ubuntu Dapper, with most latest security fixes and updates:
gtk-engines-xyz 1:2.7.4.is.2.6.10-0ubuntu1
xserver-xorg 7.0.0-ubuntu45
xserver-xorg-i810 1:1.4.1.4-0ubuntu6

Finally, there's a bug in the package description of
gtk2-engines-ubuntulooks. It says "Clearlooks". Presumably, the
description was copied from gtk2-engines-clearlooks.

Regards,
 Jörg Höhle