There is a bit more logic involved when printing a big image in an attempt to reduce the bandwidth there is sort of RLE compression step that leaves out parts of image that have single color.
I remember fixing something there a while ago; can you try with trunk first?
If it still does not work, testcase would be handy, but I can manage without.
Or you can actually try around Draw/Draw.cpp:156 to replace IsPrinter with false and report results... (that is not a fix, just test whether the problem is caused by that RLE compression).