Removing conky drop shadow

To solve these problems, don't paste the settings for opening in a new window, just delete the code.

What to delete (usually if you copied the code, it has this):

#Create own window instead of using desktop (required in nautilus)
own_window yes
own_window_hints undecorated,below,skip_taskbar
background no

I think what you need is to replace own_window_type normal with own_window_type override .

The following setting in .conkyrc solves the shadow problem.

own_window_type     override

But causes distorted fonts and plots over time.

The following options in .conkyrc solved the problem for me:

own_window_type desktop
own_window_argb_visual yes

I'm not sure how you're editing settings (the Window Decoration section of what?) but I have draw_shades no in my .conkyrc and no drop shadows. Lifehacker has a whole thread of Conky configs, too. Might be worth digging around there if you're trying to fine tune things.