I just moved all the DUI import declarations (phobos imports only)
from the class bodies to the module level
(just before the classes where they were initially)

after moving a couple back into the classes I still have:

dui/TreePath.d(59): import std conflicts with TreeIter.std at
dui/TreeIter.d(28) dui/TreePath.d(59): import std conflicts with
TreeIter.std at dui/TreeIter.d(28) dui/TreePath.d(59): import std
conflicts with TreeIter.std at dui/TreeIter.d(28) dui/TreePath.d(59):
import std conflicts with TreeIter.std at dui/TreeIter.d(28)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/DUI.d(96): import std conflicts with Bitmap.std at ddi/Bitmap.d(31)
dui/Widget.d(324): import std conflicts with Display.std at
ddi/Display.d(28) dui/DUI.d(96): import std conflicts with Bitmap.std at
ddi/Bitmap.d(31) dui/DUI.d(96): import std conflicts with Bitmap.std at
ddi/Bitmap.d(31)

dui/TreeIter.d(28)	= private import std.string;
dui/TreePath.d(59)	= private import std.string;
dui/DUI.d(96)		= private import std.string;
ddi/Bitmap.d(31)	= private import std.string;
dui/Widget.d(324)	= private import std.string;

can't reproduce it on smaller example.

Ant