While looking at the buglist, I noticed more than one mention of a missing symbol in pango.dll. This can happen if Gtk or Pangomm do not find a symbol they need. So I checked the site, and there is a new pango win32 bugfix build, and a Gtkmm bugfix release that includes, among other things, the TreeViewColumn export fix. So I assembled these two into the libs, which are here:
http://inkscape.org/win32/gtk26-050729.7z
If you are a win32 builder, let me know how they work.
I -hope- that this takes care of the missing symbol problem. I know that there are 3 missing symbols from atk.dll, but we will likely not encounter those. Little problems like these are "upstream," and we can only report them.
It would be wonderful if we could build the whole dependency tree with Mingw from source all the way up to Gtkmm and libxslt, so that we could help find these problems and lend assistance in fixing them. Maybe we can talk with the Gtk/Gtkmm guys and see about doing just that.
Bob