It works for me. In my attached savegame I can trade one of my two gold resources and the other remains available.
@wfsaxton: I can't reproduce the bug with your savegame and instructions - Ramesses says nothing could make the deal work...
Did you load the AFTER version?
It shows the resources gone.
Actually, I just tried my before and, like you, I couldn't reproduce it using my initial instructions. I did figure out how to reproduce it, though, and updated the instructions in the original post.