Is there any way to remove the original task bar from the primary display, when using the 'Show on all monitors" feature?
Using windows 8

To fix it maybe (if you cant find a better way ofcourse), youcould force the 'auto hide taskbar' option, and change the un-hide delay to some insanely large number

Can I suggest you look at these:

http://www.sevenforums.com/customization/79667-remove-taskbar-100-a.html#post696027
http://www.sevenforums.com/customization/44913-disabletaskbarontop-disable-taskbar-always-top-3.html
http://www.sevenforums.com/tutorials/54842-taskbar-always-top-disable-enable.html

As yet I have no satisfactory solution, but maybe there is something in there that can help you.
Even just adding a delay or in some way reducing the sensitivity of auot-hides opening of the native windows taskbar would be a good start.

Cheers

Okay, this isn't ideal, but I think I have finally got a workaround that people can use in the meantime:

http://www.eightforums.com/software-apps/11066-disable-taskbar-always-top.html#post275120