Looking through the files (GitHub version) while merging with my 1.5.7c test store files I may have found a possible bug.

Code:
admin/attributes_controller.php lines 1752-1755

                <!-- bof_adding -->
<!--- Dual Pricing start --->
		<tr class="attributeBoxContent"><td colspan="11"><table border="0" width="100%">
<!--- Dual Pricing end --->
There doesn't seem to be a corresponding </tr> (that I can find).

Where would I put that?